Question

there are12 identical balls of different colours in a bag .If 6 more balls of black colour are added the probability of drawing black balls became 1/12.Find no. of black balls ​

Answer 1

Answer:

3 is the answer.

Step-by-step explanation:

Initially, total number of balls =12

No. of black balls =x

So, P(black ball) =12x

If 6 more black balls are added, total number of balls =12+6=18

NO. of black balls =x+6

P(black ball) = 18x+6

Given the probability of drawing a black ball is now double of what it was before

So, 122x=18(x+6)

6x=18(x+6)

3x=x+62x=6x=3