Answer:
No of white balls = 5
Explanation:
Given that,
Total no of red balls = 4
Total no of green balls = 6
The probability of not drawing a white ball in one draw be,

We need to find the number of white balls. Let there are x balls.
The probability of drawing a white ball = 1 - the probability of not drawing a white ball
= 1 -2/3
= 1/3
Using the formula for solving probability of having a white ball.

Hence, there are 5 white balls.