Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.
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Question: peter had 33 marbles in his pocket . he lost some when he went outside to play . now he only has 18 marbles . how many marbles did peter lose ?

Answer: 15

Question: finally they had to roam around 169 factories to make sure they are throwing their wastes properly . if their group went to 69 factories and the second went to 52 how many factories remain unchecked ?

Answer: 48

Question: adam had to wash 14 loads of clothes . by noon he had only washed 8 loads . how many does he still need to wash ?

Answer:
6