80.
Explanation: when dividing by fractions here’s what I do. Instead of having a divide sign change it to a multiplication sign. Next flip your numerator and denominator of your fraction. In this case instead of 1/2 switch it to 2/1. You don’t see it but 40 is also 40/1. So multiply across aka numerator times numerator and denominator time denominator. 40 times 2 and 1 times 1. You’re left with 80/1 aka 80.
