Question

At a manufacturing plant, parts are regularly tested. Past records indicate that two percent of all parts tested are found to be defective. In a test batch of four hundred parts, how many are expected to be defective?

Answer 1

2% is the same thing as saying 2/100 parts are defective.
therefore, if 2 out of every 100 parts are defective, then you can find how many parts of the batch of 400 would be defective by multiplying
\[\frac{ 2 }{ 100 } * 400 = \frac{ 800 }{ 100 } = 8\]