The task is to generate the correct answer for a given math problem.
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Question: Problem: two pipes a and b can separately fill a cistern in 60 minutes and 75 minutes respectively . there is a third pipe in the bottom of the cistern to empty it . if all the three pipes are simultaneously opened , then the cistern is full in 50 minutes . in how much time , the third pipe alone can empty the cistern ?

Answer: 100 min


Question: Problem: the number of boxes in a warehouse can be divided evenly into 7 equal shipments by boat or 28 equal shipments by truck . what is the smallest number of boxes that could be in the warehouse ?

Answer: 28


Question: Problem: the ratio of the number of females to males at a party was 1 : 2 but when 7 females and 7 males left , the ratio became 1 : 3 . how many people were at the party originally ?

Answer:
42