Question

15. A bag contains 18 balls out of which x balls are red.
(i) If one ball is drawn at random from the bag, what is the probability that it is not red?
(ii) If 2 more red balls are put in the bag, the probability of drawing a red ball will be
9/8 times the probability of drawing a red ball in the first case. Find the 8
value of X.

Answer 1

Answer:

Complete step-by-step answer:

We have been given a bag which contains 1818 balls out of which x balls are red.

(i) It is given that one ball is drawn at random from the bag, then we need to find the probability that that ball is red.

So, the total outcomes of number of balls in the bag = 18= 18

And, the number of favourable outcomes of red balls in the bag = x= x

We know that, Probability =favourable outcomestotal outcomes=favourable outcomestotal outcomes

On applying the value in the above formula, we get

Probability of getting red ball =x18=x18

Thus, probability of red ball is x18.x18.

(ii) It is given that 22 more red balls are put in the bag then the probability of drawing a red ball will be 9898 time that of probability of red ball coming in part, we need to find the value of x.

We have been given two more red balls to put in the bag.

Now, the total outcomes of number of balls = (2+18) = 20= (2+18) = 20

So, now the number of favourable outcomes of red balls = x + 2= x + 2

The probability of getting red ball =x+220=x+220

In the question it is given that the probability of drawing a red ball will be 9898 time that of the probability of the red ball coming in part.

So, x+220= 98(x18)x+220= 98(x18)

x+220=x16x+220=x16

16x+32=20x4x=32x=816x+32=20x4x=32x=8

Thus, value of x is 8.8.