Question

A two-digit locker combination is made up of nonzero digits and no digit is repeated in any combination.

Answer 1

$|\Omega|=9\cdot8=72\\ A\cap B=\{(1,2),(1,4),(1,6),(1,8)\}\\ |A\cap B|=4\\\\ P(A\cap B)=\dfrac{4}{72}=\dfrac{1}{18}\Rightarrow \text{A}$