The task is to generate the correct answer for a given math problem.

Ex Input:
Problem: a man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph , find his average speed for the total journey ?

Ex Output:
4

Ex Input:
Problem: a rectangle having length 89 cm and width 34 cm . if the length of the rectangle is increased by eighty percent then how much percent the breadth should be decreased so as to maintain the same area .

Ex Output:
47.33 %

Ex Input:
Problem: 18 women can complete a work in 7 days and 10 children take 14 days to complete the work . how many days will 5 women and 10 children take to complete the work ?

Ex Output:
9 days