swerve wrote: ↑Fri Mar 13, 2020 7:07 am
A class contains boys and girls. What is the probability of selecting a boy from a class?
1) There are 35 students in the class.
2) The ratio of boys to girls is 3:4
The OA is
B
Source: Magoosh
Target question: What is the probability of selecting a boy from a class?
Statement 1: There are 35 students in the class
In order to determine the probability of selecting a boy, we need to know what fraction of the 35 students are boys.
So, as it stands, statement 1 is NOT SUFFICIENT
Statement 2: The ratio of boys to girls is 3:4
This means that, out of every 7 children, 3 of them are boys, and 4 of them are girls.
So,
P(selecting a boy) = 3/7
Since we can answer the
target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
