5000 jumps for 7 hours how many jump per hour?

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.

What is the sum of the first 8 terms of the geometric series

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )