Plug in values. Assume that Bob worked 100 hours in November and made $ 10/hr. In this case, Bob earned 100 × $ 10 = $ 1,000 in November. In December, he thus worked 90 hours and earned $ 11/hr. In this case, he earned 90 × 11 = $ 990 in December. Since he earned more in November,Quantity A is greater.