A can do a piece of work in 'x' days and B can do the same work in (x + 16) days. If both working together can do it in 15 days; calculate 'x'.

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.

The C.P. of an article is ₹ x which is sold for ₹ 27 at a loss of (x - 5) percent; find the value of x.

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