At noon, a tank contained 10cm of water. After several hours, it contained 7cm of water. What is the percent decrease of water in the tank?

Which best explains why this triangle is or is not a right triangle?

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?

George is putting trim around his rectangular deck, including the gate. he will need 44 feet of trim to do the entire deck. if the deck is 13 feet long, how wide is the deck?