Question

For an initial screening of an admission test, a candidate is given fifty problems to solve. If the probability that the candidate can solve any problem is 4/5, then the probability that he is unable to solve less than two problems is :
(A) 164/25(1/5)⁴⁸
(B) 201/5(1/5)⁴⁹
(C) 54/5(4/5)⁴⁹
(D) 316/25(4/5)⁴⁸

Answer 1

Answer:

Total problems = 50

P(Solving) =  4/5

P(Not solving) = 1/5

P(unable to solve less than two problems) = P(not solving one problem) + P(not solving zero problem)

( 4 /5 )^ 50 + 50 C 1 *( 1/ 5 )*$(4/5)^{49}$

.54/5(4/5)⁴⁹