Question

A bag contains 6 tennis balls and 8 cricket balls.Three balls are randomly drawn from the bag.what is the probability that atleast one of the drawn balls is cricket ball


full solution​

Answer 1

Answer:

Let drawing of a cricket ball be treated as success.

And x denote random variable of occurrence of success.

So,we are interested in p(x>=1).

This can be also computed as p(x>=1)=1-p(x=0)

Now probability of drawing a cricket ball =8/14=4/7 (since there are 8 cricket balls in 14 total balls)

The question doesn't specifies that in how many trials atleast 1 cricket ball is drawn.

Let us say total no of trials is n.

This leads to a problem of binomial distribution. Where p=4/7

Now,p(x=0)= nc0 ×(4/7)^0×(3/7)^n

=(3/7)^n

So,required probability=1-(3/7)^n

Where n is total no of trials.