Question

Yossi used to have a square garage with 354 ft² of floor space. He recently built an addition to it. The garage is still a​ square, but now it has​ 50% more floor space. What was the length of one side of the garage​ originally? What is the length of one side of the garage​ now? What was the percent increase in the length of one​ side?

Answer 1

Original length = sr(354) = 18.8 feet

New length = sr(354 x 1.5) = 23.0 feet

Percent increase = (23.0 - 18.8) / 18.8 x 100 = 22.3%

If you calculate the increase using unrounded values it is 22.4744871%. Close to 22.5%.
Avoid using rounded values in any further calculations!