Question

The probability that Rakesh will score more than 90 marks in class test is 0.75. What is the probability that Rakesh will secure more than 90 marks in three out of four class tests?

Answer 1

probability of scoring more than 90 = 0.75
so probability of
scoring 90 or less than 90 = 1- 0.75 = 0.25

Required probability = (0.75×0.75×0.75)×0.25
= 0.1054
or, you can say 10.54 % chance

because,
probability of scoring more than 90 In 3 tests out of 4 tests, that means in one test they have to score less than 90.

I hope this will help you...