‹ Back to the paper
Solve the following.
The probability that a bulb produced in a factory will fuse after 150 days of use is . Find the…
The probability that a bulb produced in a factory will fuse after 150 days of use is $0.05$. Find the probability that out of 5 such bulbs:
None will fuse after 150 days of use.
Answer
Answer
AILet $X$ = number of bulbs that fuse out of $n = 5$. $p = 0.05$, $q = 0.95$; $X$ is binomial: $P(X = r) = {}^5C_r\,p^r q^{5-r}$.
$P(X = 0) = (0.95)^5 = 0.7738$
Final answer: $0.7738$
From ISC 2020 Mathematics Paper 1, question 14(i).