You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
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Question: A waiter had 9 tables he was waiting on , with 7 women and 3 men at each table . How many customers total did the waiter have ?

Answer: 90


Question: After a party , 0.625 of the cake is left over . That night , big brother eats 0.25 of the cake . How much is left over after that ?

Answer: 0.375


Question: Gwen had 18 math problems and 11 science problems for homework . If she finished 24 of the problems at school , how many problems did she have to do for homework ?

Answer:
5