Question

In a big pool of balls, 14% are red. 150 balls are drawn randomly, approximate the probability that the number of red balls is more than 140.

Answer 1

it is a binomial probability distribution, because there is fixed number of trials,  
only two outcomes are there, success and failure  
trails are independent of each other  
and probability is given by  

P(X=x) = C(n,x)*px*(1-p)(n-x)

where  
Sample size , n =    150
Probability of an event of interest, p =   0.14

P(X>140) = 1 - ΣC(n,x)*p^x*(1-p)^(n-x) where x goes from 0 to 140

P(X>140) = 0.0000000