2 distinct integers between 5 and 17 inclusive are chosen. What is the probability that their product is odd?

Question

"Suppose two distinct integers are chosen from between 5 and 17 inclusive. What is the probability that their product is odd?"

I can't figure out the probability, although I do know that both integers must be odd in order for there to be an odd product.

Thanks

Answer 1

Guide:

• Let $A$ be the number of pairs of integers that you can choose between $5$ and $17$.

• Let $B$ be the number of pairs of odd integers that you can choose from between $5$ and $17$. You might like to investigate how many odd integers are there in the range and use similar formula as the first part.

• Divide $B$ by $A$.