Question

A school has 320 girls and 250 boys.

The probability that a girl is left-handed is 0.2
The probability that a boy is left-handed is 0.1
Estimate the number of left-handed students in the school.​

Answer 1

320 girls x 0.2 lh probability = 64 lhg
250 boys x 0.1 lh probability = 25 lhb
Total is the sum of the two 64+25 = 89