Question

Question 31(ii)
An integer is chosen between 0 and 100. What is the probability that it is not divisible by 7?

Answer 1

The number of integers between 0 and 100 is
n(S) = 99
Let $E_2$ = Event of choosing an integer which is divisible by 7
$\therefore n\left(E_2\right)=n\left(S\right)-n\left(E_1\right)$
$=99-14=85$
$\therefore P\left(E_2\right)=\frac{n\left(E_2\right)}{n\left(S\right)}=\frac{85}{99}$