Question

According to one survey in India, 75% of Instagram users love REELS. Suppose that 25

Instagram users (randomly selected) have been approached in the university located in vile

parle. They have been asked about their status of like/ dislike the Instagram- REELS.

a) What is the probability that Exactly 15 of them would agree with the claim (or said they

love Insta-REELS)?

b) What is the probability that Exactly 20 of them would agree with the claim (or said they

love Insta-REELS)?

Answer 1

Let $X=$ the number of  users who love REELS: $X\sim Bin(n, p).$

Given $n=205, p=0.75, q=1-p=0.25.$

a)

$$P(X=15)=\dbinom{25}{15}(0.75)^{15}(0.25)^{25-15}$$ $$=0.04165835$$

b)

$$P(X=20)=\dbinom{25}{20}(0.75)^{20}(0.25)^{25-20}$$ $$=0.16453759$$