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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 24 Oct 2019, 00:34
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D
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73% (02:07) correct 27% (02:47) wrong based on 532 sessions

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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain number of girls joined the class just as twice that number of boys left the class, changing the ratio of girls to boys to 7 to 4. How many boys left the class on Tuesday?

(A) 5
(B) 6
(C) 11
(D) 12
(E) 18
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D
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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 24 Oct 2019, 04:37
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8+x /20-2x = 7/4
18x=108
x =6
2x=12

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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 26 Oct 2019, 09:00
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Bunuel
On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain number of girls joined the class just as twice that number of boys left the class, changing the ratio of girls to boys to 7 to 4. How many boys left the class on Tuesday?

(A) 5
(B) 6
(C) 11
(D) 12
(E) 18
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Let g be the number of girls who joined the class on Tuesday. We can create the equation:

(8 + g)/(20 - 2g) = 7/4

4(8 + g) = 7(20 - 2g)

32 + 4g = 140 - 14g

18g = 108

g = 6

So 6 x 2 = 12 boys left the class.

Answer: D
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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 20 Jun 2020, 12:04
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ScottTargetTestPrep
Bunuel
On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain number of girls joined the class just as twice that number of boys left the class, changing the ratio of girls to boys to 7 to 4. How many boys left the class on Tuesday?

(A) 5
(B) 6
(C) 11
(D) 12
(E) 18


Let g be the number of girls who joined the class on Tuesday. We can create the equation:

(8 + g)/(20 - 2g) = 7/4

4(8 + g) = 7(20 - 2g)

32 + 4g = 140 - 14g

18g = 108

g = 6

So 6 x 2 = 12 boys left the class.

Answer: D
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Why we are subtracting 2g from boys, as it was the boys who left. So shouldn't it be (8+2b)/(20-b)?
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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 17 Jul 2020, 04:24
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lakshya14
ScottTargetTestPrep
Bunuel
On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain number of girls joined the class just as twice that number of boys left the class, changing the ratio of girls to boys to 7 to 4. How many boys left the class on Tuesday?

(A) 5
(B) 6
(C) 11
(D) 12
(E) 18


Let g be the number of girls who joined the class on Tuesday. We can create the equation:

(8 + g)/(20 - 2g) = 7/4

4(8 + g) = 7(20 - 2g)

32 + 4g = 140 - 14g

18g = 108

g = 6

So 6 x 2 = 12 boys left the class.

Answer: D

Why we are subtracting 2g from boys, as it was the boys who left. So shouldn't it be (8+2b)/(20-b)?
Show more

Response:

The exact sentence describing the relation between the number of boys who left and the number of girls who joined is “a certain number of girls joined the class just as twice that number of boys left the class.” I think you interpreted this sentence as “a certain number of girls joined the class and this number is twice the number of boys who left,” but it is not true. From this sentence, we can deduce the following: 1) a certain number of girls (g) joined the class, 2) twice that number of boys (2g) left the class. That’s why we add g to the number of girls and subtract 2g from the number of boys.
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On Monday, a class has 8 girls and 20 boys. On Tuesday, a certain numb 23 Dec 2025, 14:13
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