Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

03 Nov 2017, 15:47

Hi all, I am using OG 2018 via the online question bank and came across GMAT.IR.0020 and I'm completely stumped by this question, and the explanation of the answer makes no sense either. How can you determine how many and when children are moving into different groups?

CHARTS:

Tab 1 "CCC": The ChildCare Center (CCC) is a medium-sized child care facility that offers daytime supervision and instruction on weekdays (Monday through Friday) for children up to the age of 5. There are many children who attend CCC every weekday, and a relatively small number attend fewer than 3 days per week.

The classroom assignment and daily fee paid to CCC for each child are determined by the child's age on Friday of the previous week.

Attachment:

File comment: Tab 1 chart

GMAT.IR.0020-f0001.jpg [ 20.22 KiB | Viewed 826 times ]

Tab 2 "Regulations": The ratio of the number of classroom staf in a particular classroom to the number of children in that classroom is subject to local regulations—certain minimum staff-to-child ratios are to be met or exceeded in every classroom. The minimum ratio for a particular classroom is determined by the age of the youngest child in the classroom. The table shows these minimums. Each day CCC assigns to each classroom the least number of staff members needed to comply with the local regulations.

Attachment:

File comment: Tab 2 chart

GMAT.IR.0020-f0002.jpg [ 21.4 KiB | Viewed 822 times ]

Tab 3 "Week 2 Enrollment": The table shows the daily attendance at CCC for Week 2 of a recent fiscal year. The roster of children attending CCC—as well as the days of the week each child attended—was unchanged from Week 1 through Week 3.

Attachment:

File comment: Tab 3 chart

GMAT.IR.0020-f0003.jpg [ 23.78 KiB | Viewed 822 times ]

QUESTION:

For each of the following classrooms, select More staff if more classroom staff members were assigned to that classroom on the Monday of Week 3 than on the Monday of Week 2. Otherwise, select Same/fewer staff:

Attachment:

File comment: Question chart

GMAT.IR.0020-q.JPG [ 17.86 KiB | Viewed 817 times ]

According to the information on the Week 2 Enrollment tab, on Monday of Week 2 there were 9 children in the Twos classroom. During Week 2, as of Friday one child had turned 2 and another child had turned 3. The CCC tab indicates that a child's classroom assignment is determined by her or his age on Friday of the previous week, so the number of children in the Twos classroom was the same on Monday of Week 3 (9 + 1 – 1 = 9) as it was on Monday of Week 2. The Regulations tab indicates that CCC assigns the minimum number of staff necessary to comply with regulations, so the number of staff assigned to that classroom would have been the same on Monday of Week 3 as it was on Monday of Week 2.

The correct answer is Same/fewer staff.

B: Apply

On Monday of Week 2 there were 15 children in the Threes classroom. During Week 2, as of Friday one child had turned 3 and four children had turned 4. Given that a child's classroom assignment is determined by her or his age on Friday of the previous week, on Monday of Week 3, there were 12 children (15 + 1 – 4 = 12) in the Threes classroom. Furthermore, given that the required ratio of staff to children in the Threes classroom is 1:10, and that CCC assigns the minimum number of staff needed to comply with regulations, we can calculate the number of staff assigned to the Threes classroom for each Monday by dividing the number of children in the Threes classroom by 10 and rounding up to the nearest whole number.

Monday of Week 2: 15/10=1.5 15/10=1.5, for 2 staff.

Monday of Week 3: 12/10=1.2 12/10=1.2, for 2 staff.

Therefore, the same number of staff was assigned to the Threes classroom for Monday of Week 2 and for Monday of Week 3.

The correct answer is Same/fewer staff.

C: Apply

On Monday of Week 2 there were 12 children in the FourFives classroom. During Week 2, as of Friday four children had turned 4 and no children turned 5 or 6. Given that a child's classroom assignment is determined by her or his age on Friday of the previous week, on Monday of Week 3 the FourFives classroom had 16 children (12 + 4 = 16). Furthermore, given that the required ratio of staff to children in the FourFives classroom is 1:13, and that CCC assigns the minimum number of staff needed to comply with regulations, we can calculate the number of staff assigned to the FourFives classroom for each Monday by dividing the number of children in the FourFives classroom by 13 and rounding up to the nearest whole number.

Monday of Week 2: 12/13≈0.92 12/13≈0.92, for 1 staff.

Monday of Week 3: 16/13≈1.23 16/13≈1.23, for 2 staff.

Therefore, more staff were assigned to the FourFives classroom for Monday of Week 3 than were assigned to that classroom for Monday of Week 2.

WE: Supply Chain Management (Energy and Utilities)

The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

08 Nov 2017, 06:17

OG explanations are notorious for being lack luster. As a general thought, Id recommend getting another source - Veritas, Magoosh, Manhattan etc to learn from, and then use the OG for drilling practice closer to the end of your preparation.

Regarding the question itself, you have to really dig into this to make sense of it. Staffing needs are determined on Friday of the week prior. We have to assume that the needs were met appropriately for Monday of week 2, and we can figure out how many staff members were on given the information in the Tab 2 chart. That gives you the base number for the problem.

Then, you can look at the information for Friday of week 2 to determine how many staff members are needed for the following Monday, and that will give you the delta that is asked for in the question.

To be honest though, I can follow their logic in the answer up until "C" and then I'm lost. There is a chance the OG is incorrect (wouldn't be the first time that happened) but I'm not sure. IR is kind of quirky, and there are a lot of questions with ambiguity in them. All in all, I don't recommend spending too much time trying to study for it, there are a lot of better uses of your time and the score is not weighed nearly as much as Q or V.

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

20 Nov 2017, 13:15

RonPurewal : I am facing difficulty in understanding the question and its solution. It will be helpful ,if you can explain how to go about this problem..
_________________

Give Kudos for correct answer and/or if you like the solution.

The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

21 Nov 2017, 00:52

Bunuel -> kindly explain how to proceed in this question , In official answer the age of children changes on Friday of week 2 and i am unable to make out that how is the age changing as per attendance tab 3 chart ( WEEK 2 ATTENDANCE BY CLASS ROOM) ->?? kindly explain .... or chetan2u whether you can explain... Thanks in advance
_________________

Give Kudos for correct answer and/or if you like the solution.

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

21 Nov 2017, 17:46

well, I remember that magoosh guideline and empower gmat guideline does not mention multi-tables in IRR. Also, many gmat takers and gmat sources have assumption that IRR questions are not so much complex as this question is.

The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

24 Nov 2017, 08:39

I would love an answer from an Expert too. I can't understand the OG's explanation at all.

However, here is how I solved the answer, and that was pretty simple. Hence the reason why I have doubts about my logic.

We are asked:"For each of the following classrooms, select More staff if more classroom staff members were assigned to that classroom on the Monday of Week 3than on the Monday of Week 2. Otherwise, select Same/fewer staff"

We are told: "The classroom assignment and daily fee paid to CCC for each child are determined by the child's age on Friday of the previous week."

My understanding: we can assume that on the Monday of any week, we have the same number of child than on the previous Friday of that week. ==> The number of child on the Monday of Week 2 = the number of child on the Friday of Week 1 ==> The number of child on the Monday of Week 3 = the number of child on the Friday of Week 2

Solve: therefore, we need to determine if the change in the number of child from Week 2 to Week 3 will have an impact on the required number of staff. ==> For the "TWOs" ==> Monday Week 2 = 9 and Friday Week 2 = 6 ==> Monday Week 3 will be 6 = Same/Few Staff ==> For the "THREEs" ==> Monday Week 2 = 15 and Friday Week 2 = 12 ==> Monday Week 3 will be 12 = Same/Few Staff ==> For the "FourFives" ==> Monday Week 2 = 12 and Friday Week 2 = 8 ==> Monday Week 3 will be 8 = Same/Few Staff

In essence, for all 3 groups we will have less kids on the Monday of Week 3 than on the Monday of Week 2. At this point, we don't care about the ratios of staff to children, we just know the required number of staff will be the same or less.

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

24 Nov 2017, 10:04

Hadrienlbb wrote:

I would love an answer from an Expert too. I can't understand the OG's explanation at all.

However, here is how I solved the answer, and that was pretty simple. Hence the reason why I have doubts about my logic.

We are asked:"For each of the following classrooms, select More staff if more classroom staff members were assigned to that classroom on the Monday of Week 3than on the Monday of Week 2. Otherwise, select Same/fewer staff"

We are told: "The classroom assignment and daily fee paid to CCC for each child are determined by the child's age on Friday of the previous week."

My understanding: we can assume that on the Monday of any week, we have the same number of child than on the previous Friday of that week. ==> The number of child on the Monday of Week 2 = the number of child on the Friday of Week 1 ==> The number of child on the Monday of Week 3 = the number of child on the Friday of Week 2

Solve: therefore, we need to determine if the change in the number of child from Week 2 to Week 3 will have an impact on the required number of staff. ==> For the "TWOs" ==> Monday Week 2 = 9 and Friday Week 2 = 6 ==> Monday Week 3 will be 6 = Same/Few Staff ==> For the "THREEs" ==> Monday Week 2 = 15 and Friday Week 2 = 12 ==> Monday Week 3 will be 12 = Same/Few Staff ==> For the "FourFives" ==> Monday Week 2 = 12 and Friday Week 2 = 8 ==> Monday Week 3 will be 8 = Same/Few Staff

In essence, for all 3 groups we will have less kids on the Monday of Week 3 than on the Monday of Week 2. At this point, we don't care about the ratios of staff to children, we just know the required number of staff will be the same or less.

Hope this helps!

Unfortunately -> your answer is wrong..Sorry - it seems your logic is somehow incorrect.

abhimahna bro can you help in solving this ques.
_________________

Give Kudos for correct answer and/or if you like the solution.

ALL of the numbers in the table are based on the kids' ages on ONE specific day (...namely, friday of week 1). so, clearly, the numbers in the table can't possibly tell us anything about kids who had BIRTHDAYS (= whose ages CHANGED). accordingly, it's quite clear that we're missing some centrally important information here.

i went into the online material accompanying my copy of the OG, and, sure enough, the following entire paragraph has been left out here:

From the Saturday before Week 2 through the Friday of Week 2, exactly eight of the children in attendance at CCC had birthdays. Two children turned 1, one children turned 2, one child turned 3, and four children turned 4. All changes to classroom attendance from Week 2 to Week 3 were due to these birthdays.

please see attached screenshot.

__

...now let's all try this one again. you should find it much more ... tractable this time. hah.

due diligence, people!

Attachments

Screen Shot 2017-12-05 at 02.05'42.png [ 385.75 KiB | Viewed 196 times ]

_________________

Please visit my corners of the web: http://www.RonPurewal.com http://www.facebook.com/RonPurewalGMAT __

Pueden hacerle preguntas a Ron en castellano Potete fare domande a Ron in italiano On peut poser des questions à Ron en français Voit esittää kysymyksiä Ron:lle myös suomeksi __

Un bon vêtement, c'est un passeport pour le bonheur. —Yves Saint-Laurent

The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

05 Dec 2017, 02:24

RonPurewal wrote:

ahah isn't anyone fact-checking this stuff?

ALL of the numbers in the table are based on the kids' ages on ONE specific day (...namely, friday of week 1). so, clearly, the numbers in the table can't possibly tell us anything about kids who had BIRTHDAYS (= whose ages CHANGED). accordingly, it's quite clear that we're missing some centrally important information here.

i went into the online material accompanying my copy of the OG, and, sure enough, the following entire paragraph has been left out here:

From the Saturday before Week 2 through the Friday of Week 2, exactly eight of the children in attendance at CCC had birthdays. Two children turned 1, one children turned 2, one child turned 3, and four children turned 4. All changes to classroom attendance from Week 2 to Week 3 were due to these birthdays.

please see attached screenshot.

__

...now let's all try this one again. you should find it much more ... tractable this time. hah.

due diligence, people!

Strange enough, In my OG 2018 online edition -> i don't have this info there so i was unable to find how the birthdays are decided by official solution.

Strange enough, In my OG 2018 online edition -> i don't have this info there so i was unable to find how the birthdays are decided by official solution.

really? can you take a screenshot? that's truly bizarre... since the questions SHOULD be pulled, in real time, from the same question pool on the wiley server. (when I set up the "quiz" again, this item showed up as no. 18 instead of no. 42.)
_________________

Please visit my corners of the web: http://www.RonPurewal.com http://www.facebook.com/RonPurewalGMAT __

Pueden hacerle preguntas a Ron en castellano Potete fare domande a Ron in italiano On peut poser des questions à Ron en français Voit esittää kysymyksiä Ron:lle myös suomeksi __

Un bon vêtement, c'est un passeport pour le bonheur. —Yves Saint-Laurent

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

05 Dec 2017, 03:21

RonPurewal wrote:

sahilvijay wrote:

Strange enough, In my OG 2018 online edition -> i don't have this info there so i was unable to find how the birthdays are decided by official solution.

really? can you take a screenshot? that's truly bizarre... since the questions SHOULD be pulled, in real time, from the same question pool on the wiley server. (when I set up the "quiz" again, this item showed up as no. 18 instead of no. 42.)

Thanks for reply RonPurewal I just checked back online in OG 18 -> The lines you mentioned are now appearing, moreover i have pointed out some other mistakes in online OG (IR section) and sent mail to Wiley. In November when i was solving and was unable to comprehend the solution (official solution) since this info was not added that time. So i came to gmat club and asked for reply. Also ditto question, which appeared to me in OG online is written in this forum above. And as you can see apart from myself there are 2 persons - one who posted the solution and other one who replied to his post were also unable to comprehend.

So i tagged you to explain me-> but after seeing this crucial info , which was not available to me I can understand the logic.

See the attachment -> this info is appearing now. It can be a technical issue possibly or they have corrected it.

Attachments

Untitled.jpeg [ 508.85 KiB | Viewed 171 times ]

_________________

Give Kudos for correct answer and/or if you like the solution.

Ahha it's possible that the copy-editing / quality-control person was just asleep (or drunk?) when this one came across his/her desk. ...because the second tab STILL says: "The ratio of the number of classroom staf in a particular classroom..." that's pretty bad.

so, it's not farfetched at all to suppose that the same editor simply failed to notice that a whole paragraph had gone missing from the earlier version. ?
_________________

Please visit my corners of the web: http://www.RonPurewal.com http://www.facebook.com/RonPurewalGMAT __

Pueden hacerle preguntas a Ron en castellano Potete fare domande a Ron in italiano On peut poser des questions à Ron en français Voit esittää kysymyksiä Ron:lle myös suomeksi __

Un bon vêtement, c'est un passeport pour le bonheur. —Yves Saint-Laurent

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

05 Dec 2017, 05:23

This online platform is a joke. I can't believe the OG platform would make such mistakes. The time and energy I expanded on this question (and the frustration lol), all that because of a missing paragraph XD

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

05 Dec 2017, 05:27

Hadrienlbb wrote:

This online platform is a joke. I can't believe the OG platform would make such mistakes. The time and energy I expanded on this question (and the frustration lol), all that because of a missing paragraph XD

Posted from my mobile device

you cant imagine how hard i struggled to even understand the OG 's explanation , which was going above my head due to missing text. Also it is strange that they somehow came to know about this issue ->
_________________

Give Kudos for correct answer and/or if you like the solution.

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

09 Dec 2017, 01:56

cxa0897 wrote:

OG explanations are notorious for being lack luster. As a general thought, Id recommend getting another source - Veritas, Magoosh, Manhattan etc to learn from, and then use the OG for drilling practice closer to the end of your preparation.

Regarding the question itself, you have to really dig into this to make sense of it. Staffing needs are determined on Friday of the week prior. We have to assume that the needs were met appropriately for Monday of week 2, and we can figure out how many staff members were on given the information in the Tab 2 chart. That gives you the base number for the problem.

Then, you can look at the information for Friday of week 2 to determine how many staff members are needed for the following Monday, and that will give you the delta that is asked for in the question.

To be honest though, I can follow their logic in the answer up until "C" and then I'm lost. There is a chance the OG is incorrect (wouldn't be the first time that happened) but I'm not sure. IR is kind of quirky, and there are a lot of questions with ambiguity in them. All in all, I don't recommend spending too much time trying to study for it, there are a lot of better uses of your time and the score is not weighed nearly as much as Q or V.

How about EA test, where IR is included in total score? As for this question, I actually hate it because, because for IR 0020 according to official explanation they use the number of children on Monday for purposes of determining whether they need for staff taking into account birthdays, whereas on the next question (IR 0021) they use the number of children on Friday for determining whether the combination of classes would reduce the number of staff! In fact for one of the 3 option choices this difference gives a different outcome. I think it is mistake. Some of children have 3 days a week and most 5 days of week, so missing this information, it is not possible to assume which day of the week should be the basis, but why it should be a different day of the week then? There are generally more children on Monday than on Friday, so it seems like like some children miss Friday because of 3 day schedule, but it is just a guess. It is either IR 0021 or IR 0020 that must be wrong...

Re: The ChildCare Center (CCC) is a medium-sized child care facility that [#permalink]

Show Tags

09 Dec 2017, 02:16

To further illustrate: They say "There are many children who attend CCC every weekday, and a relatively small number attend fewer than 3 days per week" It is not clear whether relatively small number can drive change in number of the staff or not, I assume yes, because we're talking about rounded numbers, even 12.1 makes it 13 for instance. Now look at the table - there were 15 children on Monday and 16 on Tuesday and Thursday and only 12 children on Friday for the group of Threes. Why? They don't tell and this question does not include information on birthdays (unlike question IR 00020), so we must assume no birthday, ok, then it is reasonable to assume that 3 children had a day off on Friday! No other explanation is possible as they do not cite any other reasons. Fine, then contrary to the OG, we must use the figure of 16 children for the group of Three for calculation purpose, but the OG uses a figures of 12!