Question

A box contains 12 balls of which some are red in colour if 6 more red ball are put in the box and a ball is drawn at random the probability of drawing a red ball doubles then what it was before find the number of red balls in bag.​

Answer 1

Answer:

Step-by-step explanation:

Let the number of red balls initially be x

P(getting a red ball) = x/12

If 6 more red balls are added

P(getting a red ball)= (x+6)/12

2 x (x/12) = (x+6)/12

x/6 = (x+6)/12

12x =6x +36

6x = 36

x=6

∴ Intial number of red balls is 6