One pipe can fill a cistern in 3 hours less than the other. The two pipes together can fill the cistern in 6 hours 40 minutes. Find the time that each pipe will take to fill the cistern.

A trader bought an article for ₹ x and sold it for ₹ 52, thereby making a profit of (x - 10) percent on his outlay. Calculate the cost price.

The C.P. of an article is ₹ x which is sold for ₹ 152 at a profit of (x + 10)%. Find the value of x.