A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn

• Statistics
• Probability

A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn, one-by-one, with replacement, then the variance of the number of green balls drawn is:

1. 12/5
2. 6
3. 4
4. 6/25

Solution

p = 15/25

q = 10/25

n = 10

σ² = npq

= 12/5

The correct option is A.