Question

a box contains 24 balls of which some are yellow in colour if 12 more yellow balls are put into the box and a ball is drawn at random the probability of drawing in yellow ball Doubles that what it was before find the number of yellow balls in the bag

Answer 1

Answer:

Step-by-step explanation:

Let the number of yellow balls be x.

P(yellow ball) = x/24

Now,12 more yellow balls are put in the box.

Total no. of balls = 24 + 12 = 36

No. of yellow balls = x + 12

P(yellow balls after adding 12 yellow balls) = (x+12)/36

2 times of P(yellow ball)=P(yellow balls after adding 12 yellow balls)

2*x/24 = (x+12)/36

x/12 = (x+12)/36

36*x = 12*(x+12)

36x = 12x+144

36x - 12x=144

24x = 144

x=144/24

x=6

There are 6 yellow balls in the box

Answer 2

Answer:

Step-by-step explanation:

Let the no. of yellow balls be x. In 1st case, P(getting a yellow balls)=x/24 Now, in 2nd case P(getting a yellow balls)=x+12/36 Now, according to the question, =x+12/36 = 2( x/24), 12x + 144 = 36x. =24x = 144 , x=6. Hence, total no. of yellow balls are 6