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

Q: Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively , while the third empty it in 30 hr . if all pipes are opened simultaneously , then the cistern will be filled in

A: 6.67 hr
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Q: Problem: how much interest will $ 8,000 earn in 9 months at an annual rate of 6 % ?

A: $ 360
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Q: Problem: a reduction of 20 % in the price of salt enables a lady to obtain 10 kgs more for rs . 200 , find the original price per kg ?

A:
s . 5
****