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The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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13 Oct 2017, 21:42
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The girl:boy ratio in class A was 1:3 and the same ratio in Class B was 2:1. When the two classes were combined, the ratio became 1:1. If class A had 24 girls, how many students did class B have? A) 48 B) 72 C) 96 D) 120 E) 144
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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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14 Oct 2017, 02:33
Weighted average question. !!! For class A : girls : x boys : 3x For class B : girls : 2y boys : y total students : 3y Now since the ration is 1:1 total number of boys = total number of girls 3x + y = x + 2y therefore y = 2x Now, since x = 24 y = 48 and 3y = 144
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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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14 Oct 2017, 05:52
saba4010 wrote: The girl:boy ratio in class A was 1:3 and the same ratio in Class B was 2:1. When the two classes were combined, the ratio became 1:1. If class A had 24 girls, how many students did class B have?
A) 48 B) 72 C) 96 D) 120 E) 144 No of girls in class \(A =24\) therefore, no of boys in class \(A = 3*24=72\) (from this we can easily eliminate option A, B & C) let number of girls in class \(B\) be \(2x\) and no of boys be \(x\). So total students in class \(B =3x\) When Class \(A\) and \(B\) are mixed its given no boys=no of girls or \(24+2x=72+x => x=48\) Hence \(3x= 3*48=144\) Option E



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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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14 Oct 2017, 06:01
Class A => Ratio G:B = 1:3 Where G is number of girls and B is number of boys. Given G=24 for class A. B=24x3=72. In class B, G:B = 2:1 When combining both classes, ratio = 1:1 Therefore, 24+G:72+B=1:1 Solving we get, 24+G=72+B G=48+B(1) From ratio of class B, we get G=2B(2) Solving equations (1) and (2) B = 48 and G=96 Total students in class B= 48+96=144 Answer E.
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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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14 Oct 2017, 06:10
Class A G:B = 1:3. Class A had 24 girls, thus Class A has 24*3 = 72 boys. Class B G:B = 2:1. Let the number of boys in class B be x. Thus, the number of girls in Class B is 2x. It's mentioned that on combining class A and B, the ratio became 1:1 (boys became equal to girls, effectively) Thus, total number of boys (A and B) = total number of girls (A and B) > (72+x)=(24+2x) > x = 48. There are a total of (x+2x = 3x) students in the combined class. Thus, total number of students = 3x = 3*48 = 144.
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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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14 Oct 2017, 07:09
saba4010 wrote: The girl:boy ratio in class A was 1:3 and the same ratio in Class B was 2:1. When the two classes were combined, the ratio became 1:1. If class A had 24 girls, how many students did class B have?
A) 48 B) 72 C) 96 D) 120 E) 144 Class A : Girl : Boy = 1:3 No. of girls = 24 No. of boys = 24*3 = 72 Total = 24 + 72 = 96 Class B : Girl : Boy = 2:1 Let no. of girls & boys are 2x & x respectively Total = 2x + x = 3x Now they are mixed and the ratio is 1:1 So, 24 + 2x = 72 + x x = 48 Also total no. of students in class B = 3x = 3 * 48 = 144 Answer E



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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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30 Jun 2018, 16:07
VeritasPrepKarishma how can we solve this question using the formula from mixtures? I get this and I don't know where is my error: 24/w= (1/2)(1/4) / (2/3)(1/2) So then w= 36 (# of girls in class B) And 36 + 36/2= 56 (# of students in class B)



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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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30 Jun 2018, 16:17
24+2x=72+x X=48 3x=144 Answer E
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The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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04 Jul 2018, 19:26
saba4010 wrote: The girl:boy ratio in class A was 1:3 and the same ratio in Class B was 2:1. When the two classes were combined, the ratio became 1:1. If class A had 24 girls, how many students did class B have?
A) 48 B) 72 C) 96 D) 120 E) 144 Since class A has 24 girls, there are 24 x 3 = 72 boys in the class. We also know that in class B, the ratio of girls : boys = 2x : x The new combined ratio of 1:1 can be expressed as 1/1, or 1. We can thus create the equation: (24 + 2x)/(72 + x) = 1 24 + 2x = 72 + x x = 48 Class B had x = 48 boys and 2x = 96 girls, so class B had 48 + 96 = 144 total students. Answer: E
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Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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08 Dec 2019, 05:17
saba4010 wrote: The girl:boy ratio in class A was 1:3 and the same ratio in Class B was 2:1. When the two classes were combined, the ratio became 1:1. If class A had 24 girls, how many students did class B have?
A) 48 B) 72 C) 96 D) 120 E) 144 Class A boys  72 girls  24 Class B Boys  x girls  2x after combining 72+ x = 24 +2x x = 48 Class B students 3*48 = 144 E is correct




Re: The girl:boy ratio in class A was 1:3 and the same ratio in Class B
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