A quality-control inspector examined 220 calculators and found 10 of them to be defective. At this rate, how many defective calculators will there be in a batch of 21,780 calculators?
A) 990 calculators
B) 2200 calculators
C) 99 calculators
D) 10 calculators

Question

Quizplus · Accepted Answer

The rate of defective calculators is 10 out of 220, which simplifies to 1 out of 22. To find the number of defective calculators in a batch of 21,780, divide 21,780 by 22, which gives 990 defective calculators.

A Quality-Control Inspector Examined 220 Calculators and Found 10 of Them