jjjinapinch wrote:In Mr. Smith's class, what is the ratio of the number of boys to the number of girls?

(1) There are 3 times as many girls as boys in Mr. Smith's class.
(2) The number of boys is 1/4 of the total number of boys and girls in Mr. Smith's class.

Official Guide question
Answer: D

Target question: What is the ratio of the number of boys to the number of girls?

Statement 1: There are 3 times as many girls as boys in Mr. Smith's class.
This means there are 3 girls for every 1 boy
So, the ratio of the number of boys to the number of girls = 3 : 1
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: The number of boys is 1/4 of the total number of boys and girls in Mr. Smith's class.
So, for every 4 children there are 3 girls and 1 boy
So, the ratio of the number of boys to the number of girls = 3 : 1
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent

Hi ALL,

We're asked for the ratio of the number of boys to the number of girls in Mr. Smith's Class. This question can be solved in a couple of different ways, including by TESTing VALUES.

1) There are 3 times as many girls as boys in Mr. Smith's class.

Based on the information in Fact 1, there could be....
1 boy and 3 girls, so the ratio is 1:3
2 boys and 6 girls, so the ratio is 2:6 = 1:3
3 boys and 9 girls, so the ratio is 3:9 = 1:3
Etc.
The ratio will ALWAYS be 1:3
Fact 1 is SUFFICIENT

2) The number of boys is 1/4 of the total number of boys and girls in Mr. Smith's class.

Based on the information in Fact 2, there could be....
1 boy and 4 total children (so there are 3 girls), so the ratio is 1:3
2 boys and 8 total children (so there are 6 girls), so the ratio is 2:6 = 1:3
3 boys and 12 total children (so there are 9 girls), so the ratio is 3: 9 = 1:3
Etc.
The ratio will ALWAYS be 1:3
Fact 2 is SUFFICIENT

Final Answer: D

GMAT assassins aren't born, they're made,
Rich