Question

A random number generator chooses 2 numbers between 1 and 5 what is the probability that the computer will pick 1 and 2

Answer 1

$|\Omega|=\binom{5}{2}=\dfrac{5!}{2!3!}=\dfrac{4\cdot5}{2}=10\\ |A|=1\\\\ P(A)=\dfrac{1}{10}=10\%$