Out of 100 people selected at random, 10 have common cold. If five persons selected at random from the group, then the probability that at most one person will have common cold is

Step-by-step solution

(C) Let probability of having common cold p = 10 100 = 1 10 q = 9 10 Here n =5 , and x =0,1 . Hence required probability array l = ⁵ C ₀ ( 1 10 )⁰ ( 9 10 )⁵+ ⁵ C ₁ ( 1 10 )¹ ( 9 10 )⁴ = ( 9 10 )⁵+ 5(9)⁴ (10)⁵ = (9⁴ )[9+5] (10)⁵ = 81 81 14 10⁵ =0.9185 array