NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 04:05 It is currently 26 Apr 2024, 04:05
Decision Tracker
My Rewards
New posts
New comers' posts

Close
GMAT Club Daily Prep
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

In a certain summer school program, there are five periods in the day.

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
P
Mkrishnabdrr
Manager
Manager
Joined: 13 Aug 2015
Posts: 202
Own Kudos [?]: 322 [11]
Given Kudos: 68
GMAT 1: 710 Q49 V38
GPA: 3.94
WE:Corporate Finance (Non-Profit and Government)
Send PM
GMAT ToolKit User Reviews Badge
In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 06:24
3
Kudos
8
Bookmarks
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

84% (01:11) correct 16% (01:41) wrong based on 287 sessions
Hide Show timer Statistics
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

A. 20
B. 24
C. 100
D. 120
E. 135
ShowHide Answer
Official Answer
B
Most Helpful Reply
User avatar
L
BrentGMATPrepNow
GMAT Club Legend
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6818
Own Kudos [?]: 29938 [6]
Given Kudos: 799
Location: Canada
Send PM
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   29 Aug 2018, 16:29
5
Kudos
1
Bookmarks
Expert Reply
Top Contributor
mkrishnabdrr wrote:
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

A. 20
B. 24
C. 100
D. 120
E. 135


Take the Science, and Science Lab classes and "glue" them together to get the super class "Science-Science-Lab"
This ensures that Science Lab immediately follows the Science class

So, we now have only 4 classes: English, Math, History and Science-Science-Lab
We can arrange n objects in n! ways.
So, we can arrange these 4 classes in 4! ways (i.e. 24 ways)

Answer: B

Cheers,
Brent
General Discussion
User avatar
P
Mkrishnabdrr
Manager
Manager
Joined: 13 Aug 2015
Posts: 202
Own Kudos [?]: 322 [1]
Given Kudos: 68
GMAT 1: 710 Q49 V38
GPA: 3.94
WE:Corporate Finance (Non-Profit and Government)
Send PM
GMAT ToolKit User Reviews Badge
In a certain summer school program, there are five periods in the day. [#permalink] New post   Updated on: 04 Jul 2017, 06:39
Science cannot be placed in last slot because it must be followed by Science Lab. So, science has 4 possibilities. Science lab has to be placed immediately after science so it has 1 possibility. English 3, and Math 2. So, by fundamental counting principle, total ways=4 x 1 x 3 x 2=4 x6=24
Hence, B

Originally posted by Mkrishnabdrr on 04 Jul 2017, 06:29.
Last edited by Mkrishnabdrr on 04 Jul 2017, 06:39, edited 1 time in total.
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92929
Own Kudos [?]: 619125 [2]
Given Kudos: 81609
Send PM
CAT Tests Forum Quiz Mode
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 06:30
1
Kudos
1
Bookmarks
Expert Reply
mkrishnabdrr wrote:
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

A. 20
B. 24
C. 100
D. 120
E. 135


Science, and Science Lab are fixed, so we have 4 units:

{English}, {Math}, {History}, {Science, and Science Lab}

The number of arrangements = 4! = 24.

Answer: B.
User avatar
L
generis
Senior SC Moderator
Joined: 22 May 2016
Posts: 5330
Own Kudos [?]: 35495 [0]
Given Kudos: 9464
Send PM
CAT Tests
In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 15:57
Expert Reply
mkrishnabdrr wrote:
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

A. 20
B. 24
C. 100
D. 120
E. 135

These arrangements are small enough that you could write them out.

There's only one way to put SC and SL together in each arrangement; then multiply.

SC - SL - 3 - 2 - 1 = 6

3 - SC - SL - 2 - 1 = 6

3 - 2 - SC - SL - 1 = 6

3 - 2 - 1 - SC - SL = 6

6 * 4 = 24

Answer B
User avatar
B
ameyaprabhu
Manager
Manager
Joined: 28 Apr 2016
Posts: 71
Own Kudos [?]: 23 [0]
Given Kudos: 79
Send PM
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 21:51
mkrishnabdrr wrote:
Science cannot be placed in last slot because it must be followed by Science Lab. So, science has 4 possibilities. Science lab has to be placed immediately after science so it has 1 possibility. English 3, and Math 2. So, by fundamental counting principle, total ways=4 x 1 x 3 x 2=4 x6=24
Hence, B



Hi,

IF the question said that 'the science and science lab class must always be together', then will the answer still remain the same?
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92929
Own Kudos [?]: 619125 [0]
Given Kudos: 81609
Send PM
CAT Tests Forum Quiz Mode
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 22:05
Expert Reply
ameyaprabhu wrote:
mkrishnabdrr wrote:
Science cannot be placed in last slot because it must be followed by Science Lab. So, science has 4 possibilities. Science lab has to be placed immediately after science so it has 1 possibility. English 3, and Math 2. So, by fundamental counting principle, total ways=4 x 1 x 3 x 2=4 x6=24
Hence, B



Hi,

IF the question said that 'the science and science lab class must always be together', then will the answer still remain the same?


If it were: "in how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class or vise-versa?", then the answer would be 4!*2, because Science, and Science Lab within their unit can be arranged in two ways: {Science, and Science Lab} and {Science Lab and Science}.
User avatar
B
ameyaprabhu
Manager
Manager
Joined: 28 Apr 2016
Posts: 71
Own Kudos [?]: 23 [0]
Given Kudos: 79
Send PM
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   04 Jul 2017, 22:50
Bunuel wrote:
ameyaprabhu wrote:
mkrishnabdrr wrote:
Science cannot be placed in last slot because it must be followed by Science Lab. So, science has 4 possibilities. Science lab has to be placed immediately after science so it has 1 possibility. English 3, and Math 2. So, by fundamental counting principle, total ways=4 x 1 x 3 x 2=4 x6=24
Hence, B


Thanks, that was my exact doubt.
User avatar
S
VodkaHelps
Manager
Manager
Joined: 01 Nov 2017
Posts: 78
Own Kudos [?]: 65 [0]
Given Kudos: 171
GMAT 1: 640 Q49 V28
GMAT 2: 700 Q50 V35
GMAT 3: 680 Q47 V36
GPA: 3.84
Send PM
Reviews Badge
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   19 Sep 2018, 03:53
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?


We have 5 items, E M H S L. We need to find how many unique orders can be created from those 5 items while having L following right after S. We GLUE S and L together as 1 item. Then we have only 4 items in total E M H SL.

Ways to organize E M H SL = 4!
If the question says "Science and Science Lab must be adjacent to each other" then we will have to multiple 4! with 2 because S and L can switch places (therefore having a different order). In this question the positon of L is fixed after S. So we keep 4! as is. ANSWER IS 4!
avatar
mbaprep2020
Intern
Intern
Joined: 17 Feb 2020
Posts: 6
Own Kudos [?]: 1 [0]
Given Kudos: 0
Send PM
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   17 Feb 2020, 23:16
English, Math, History, Science

4! = 24
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22055 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   13 Dec 2020, 06:17
Expert Reply
mkrishnabdrr wrote:
In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab. In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

A. 20
B. 24
C. 100
D. 120
E. 135

Solution:

We can group Science and Science Lab together as one class, so there are actually 4 classes to be arranged; the number of ways to arrange them is 4! = 24.

Answer: B
User avatar
L
Kinshook
GMAT Club Legend
GMAT Club Legend
Joined: 03 Jun 2019
Posts: 5344
Own Kudos [?]: 3965 [0]
Given Kudos: 160
Location: India
Schools: HBS '22 CBS '22 Wharton '22
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Send PM
Reviews Badge
Re: In a certain summer school program, there are five periods in the day. [#permalink] New post   13 Dec 2020, 08:13
Given: In a certain summer school program, there are five periods in the day. Each student takes English, Math, History, Science, and Science Lab.
Asked: In how many orders can a student schedule be arranged given that Science lab must immediately follow the Science class?

We have 4 options available
1. English
2. Math
3. History
4. Science and science lab

Number of ways to arrange the 4 options = 4! = 24

IMO B
GMAT Club Bot
gmatclubot
Re: In a certain summer school program, there are five periods in the day. [#permalink]
13 Dec 2020, 08:13
Moderators:
Bunuel
Math Expert
92929 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions