Mr. Choi is painting classrooms that are all the same size. If he used 2 gallons of paint for 3 rooms, how many rooms can he paint with 4 gallons?

The length of each stair is 11 inches. what is the rise, r, for each stair? round to the nearest inch. 2 inches 7 inches 17 inches 24 inches

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

If $740 is invested at an interest rate of 11% per year and is compounded continuously, how much will the investment be worth in 7 years? use the continuous compound interest formula a = pert.