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

Q: Problem: if the personal income tax rate is lowered from 46 % to 32 % , what is the differential savings for a tax payer having an annual income before tax to the tune of $ 36000 ?

A: $ 5040
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Q: Problem: the length of a rectangle is increased by 15 % and its breadth is decreased by 20 % . what is the effect on its area ?

A: 920
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Q: Problem: a man rows his boat 75 km downstream and 45 km upstream , taking 5 hours each time . find the speed of the stream ?

A:
3 kmph
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