45 is 15% of 300. Steps to solve "45 is 15 percent of what number?" We have, 15% × x = 45; or, 15 / 100 × x = 45; Multiplying both sides by 100 and dividing both sides by 15, we have x = 45 × 100 / 15; x = 300. If you are using a calculator, simply enter 45×100÷15, which will give you the answer.
