A class of 21 students has 9 girls and 12 boys. What is the probability of a teacher randomly picking on a boy?

A. 3/4
B. 4/7
C. 3/7
D. 4/3
The correct answer is B. 4/7

4 answers

Right.
how?
12 boys out of 21 = 12/21

Divide both by 3 to reduce and you get 4/7
That makes so much since. Thank you.