Question

A bag contains 3 red balls and some black balls if the probability of drawing a black ball is double that of red ball find the probability of black balls in the bag

Answer 1

If the chances of drawing a black ball is double the chances of drawing a red ball, the number of black balls must be double that of the red ball. So, 3 x 2 = 6 black balls. Your chances of drawing a black balls is 6 chances over 9 total balls. $\frac{6}{9}$ can be simplified to $\frac{2}{3}$