problem:
2.5% of 800 engine blocks were defective.
How many defective engine blocks were made?
answer:
1. step: given/wanted
given: the base value (engines) = 800 the rate = 2.5 %
wanted: part (defective engines)
2. step formula:
part = base * rate : 100
part = 800 * 2.5 : 100
part = 20 engine blocks
20 defective engine blocks were made.