Question

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

Answer 1

Answer:

3

Step-by-step explanation:

Total balls=12

Let the red balls be x

So,

P

1

=

12

x

If the red balls increased to 6 then,

Total balls will be =12+6=18

Red balls will be=x+6

So,

P

2

=

18

x+6

Now,

12

x

=

18

x+6

x=

3

x+6

3x=x+6

2x=6

x=3