GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 22 Jan 2020, 12:19

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

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

At a certain school, the ratio of the number of second grade

Author Message
TAGS:

Hide Tags

Intern
Joined: 23 Mar 2016
Posts: 24
Schools: Tulane '18 (M\$)
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

02 May 2016, 15:01
super simple, just a minute and you're done (if not quicker)

given

1) 1s:2n......... 2n:4th ........3r:4th
2) 3:4 .............8:5............3:2
3) 6:8:5 .... 3:2
(6:8:5)*2 ...(3:2)*5
(12:16:10) (15:10)
12:16:15:10
12:15 = 1st:3rd
(12:15)/3 = 4:5
Manager
Joined: 17 Jul 2016
Posts: 54
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

18 Dec 2017, 11:11
2nd to 4th= 8/5
1st to 2nd= 3/4 = 6/8
3rd to 4th= 3/2

let 1st=6
2nd=8
4th=5
3rd is 1.5 times 4th so 1.5 (5)=7.5

1st to 3rd= 6/7.5=12/15=4/5
VP
Joined: 07 Dec 2014
Posts: 1228
At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

18 Dec 2017, 21:44
BANON wrote:
At a certain school, the ratio of the number of second graders to the number of fourth graders is 8 to 5, and the ratio of the number of first graders to the number of second graders is 3 to 4. If the ratio of the number of third graders to the number of fourth graders is 3 to 2, what is the ratio of the number of first graders to the number of third graders?

A. 16 to 15
B. 9 to 5
C. 5 to 16
D. 5 to 4
E. 4 to 5

g1:g2=3:4=12:16
g2:g4=8:5=16:10
g4:g3=2:3=10:15
g1:g3=12:15=4 to 5
E
IIMA, IIMC School Moderator
Joined: 04 Sep 2016
Posts: 1381
Location: India
WE: Engineering (Other)
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

12 Jan 2018, 23:05
Bunuel niks18 amanvermagmat

Based on fact that for equating two ratio I need common denominator, can I approach the problem
taking LCM of all no from 8 to 2?
_________________
It's the journey that brings us happiness not the destination.

Feeling stressed, you are not alone!!
Retired Moderator
Joined: 25 Feb 2013
Posts: 1156
Location: India
GPA: 3.82
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

12 Jan 2018, 23:29
Bunuel niks18 amanvermagmat

Based on fact that for equating two ratio I need common denominator, can I approach the problem
taking LCM of all no from 8 to 2?

can you explain your process in detail? I am not sure what are you going to do with LCM and how you are going to arrive at the final answer using the approach.
Intern
Joined: 31 May 2015
Posts: 1
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

23 Jan 2018, 13:36
Let,

Given info:

B/D = 8/5
A/B = 3/4
C/D = 3/2
A/C = ?

Find two equations from above which have "A" and "C"

A/B/C/D = 3/4/3/2 => A*D/C*B = 3*2/4*3 => 1/2

Now substitute B/D information (given) in the above equation

A*5/C*8 = 1/2 => A/C = 4/5
Intern
Joined: 13 Jan 2018
Posts: 5
GMAT 1: 760 Q55 V50
GPA: 3.59
At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

04 Mar 2018, 05:05
Bunuel wrote:
BANON wrote:
At a certain school, the ratio of the number of second graders to the number of fourth graders is 8 to 5, and the ratio of the number of first graders to the number of second graders is 3 to 4. If the ratio of the number of third graders to the number of fourth graders is 3 to 2, what is the ratio of the number of first graders to the number of third graders?

A. 16 to 15
B. 9 to 5
C. 5 to 16
D. 5 to 4
E. 4 to 5

Let # of first, second, third and fourth graders be A, B, C and D respectively. Question: $$\frac{A}{C}$$;

Given: $$\frac{B}{D}=\frac{8}{5}$$, $$\frac{A}{B}=\frac{3}{4}$$, and $$\frac{C}{D}=\frac{3}{2}$$;

Equate D's: $$\frac{B}{D}=\frac{8}{5}=\frac{16}{10}$$ --> $$\frac{C}{D}=\frac{3}{2}=\frac{15}{10}$$. Now, equate B's: $$\frac{A}{B}=\frac{3}{4}=\frac{12}{16}$$;

$$\frac{A}{C}=\frac{12}{15}=\frac{4}{5}$$.

B/D=8/5, C/D=3/2, A/B=3/4
B/C = B/D *D/C = 8/5 * 2/3 = 16/15
A/C = A/B * B/C = 3/4 * 16/15 = 4/5
Intern
Joined: 08 Jan 2013
Posts: 1
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

18 Aug 2018, 04:04
Please can someone help on how A/C=3/4=12/16. where did the 4 come from? Thanks
Non-Human User
Joined: 09 Sep 2013
Posts: 14002
Re: At a certain school, the ratio of the number of second grade  [#permalink]

Show Tags

22 Aug 2019, 03:12
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: At a certain school, the ratio of the number of second grade   [#permalink] 22 Aug 2019, 03:12

Go to page   Previous    1   2   [ 29 posts ]

Display posts from previous: Sort by