Question

a box contains 12 balls of which some are red in colour is 6 more red balls 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

Answer 1

confusing but easy

2/18 = 1/9

Answer 2

Answer:

3

Step-by-step explanation:

Let the no.of red balls be x.

Probability of drawing a red ball=x/12

If 6 balls are added, total no of balls=12+6=18

and Probability of drawing a red ball=x+6/18

According to the question,

2*x/12 = x+6/18

x/6=x+6/18

By cross multiplying,

18x=6(x+6)

18x=6x+36

18x-6x=36

12x=36

x=36/12

x=3.

So there were 3 red balls initially.