What will the equation be for 80 books and 4 boxes

Angles r and s are complementary. the measure of angle r is 31 degrees. which equation can be used to find angle s?

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour. what is the cyclist average rate for the round trip in miles per hour ?

What’s the range cuz i can’t find it?