You are given a math word problem and you are supposed to apply multiplication or division mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

A painter needed to paint 12 rooms in a building . Each room takes 7 hours to paint . If he already painted 5 rooms , how much longer will he take to paint the rest ?
49

63 people are going to the zoo . There are 3 cars to take people to the zoo . How many will go in each car if the same number go in each car ?
21

At lunch a waiter had 9 customers and 5 of them did n't leave a tip . If he got $ 8 each from the ones who did tip , how much money did he earn ?
32