A battery has enough energy to operate eight toy bears for 21 hours. For how long could the battery operate 15 toy bears?

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Which of the following is the correct ratio for converting kilograms to grams

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?