Question

There are 12 balls in a bag, out of which some are black balls. If 6 more black balls are put in the bag, the probability of drawing a black ball is now double of what it was before adding the 6 more black balls.
Find the original number of black balls. i.e before adding 6 more black balls.​

Answer 1

Answer:

12 balls tell it is correct or not

Answer 2

3

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) = 18 (x+6)

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

So, 12

2x = 18 (x+6)

6x = 18 (x+6)

3x=x+6

2x=6

x=3

So, the number of black balls present initially =3.