Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 20 May 2013, 07:32

# The ratio of boys to girls in Class A is 3 to 4. The ratio

Author Message
TAGS:
Senior Manager
Joined: 21 Jun 2006
Posts: 292
Followers: 1

Kudos [?]: 3 [0], given: 0

The ratio of boys to girls in Class A is 3 to 4. The ratio [#permalink]  16 Jun 2007, 22:04
The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 4 to 5. If the two classes were combined, the ratio of boys to girls in the combined class would be 17 to 22. If the number of boys in Class B is one less than the number of boys in Class A, and if the number of girls in Class B is two less than the number of girls in Class A, how many girls are in Class A?
Director
Joined: 13 Mar 2007
Posts: 555
Schools: MIT Sloan
Followers: 4

Kudos [?]: 3 [0], given: 0

12 girls.

b/g = 3/4

(b+b-1)/(g+g-2) = 17/22

solving, g = 12
Director
Joined: 26 Feb 2006
Posts: 919
Followers: 3

Kudos [?]: 28 [0], given: 0

Re: Ratios? [#permalink]  16 Jun 2007, 22:30
ArvGMAT wrote:
The ratio of boys to girls in Class A is 3 to 4. The ratio of boys to girls in Class B is 4 to 5. If the two classes were combined, the ratio of boys to girls in the combined class would be 17 to 22.

If the number of boys in Class B is one less than the number of boys in Class A, and if the number of girls in Class B is two less than the number of girls in Class A, how many girls are in Class A?

Class A:
girls = g + 1
boys = b + 2

Class B:
girls = g
boys = b

from A + B: (g+1+g) / (b+2+b) = 17/22
from A: (g+1) / (b+2) = 3/4

solving the above equation g = 10
so the number of girls in class A = 10 + 2 = 12
Manager
Joined: 17 May 2007
Posts: 181
Followers: 1

Kudos [?]: 6 [0], given: 0

Number of girls in the class A is 12
Similar topics Replies Last post
Similar
Topics:
The ratio of boys to girls in the junior class is 2 to 3 8 21 Feb 2005, 08:43
The ratio of boys to girls in Class A is 3 to 4. The ratio 8 10 Nov 2007, 06:25
8 The ratio of boys to girls in Class A is 3 to 4. The ratio 17 03 Apr 2010, 12:57
Boys to Girls Ratio 2 06 May 2010, 15:35
5 In a certain school, the ratio of boys to girls is 5 to 13. 3 24 Sep 2012, 04:12
Display posts from previous: Sort by