A pipe can fill a tank in x hours and an another can empty it in y hours. In how many hours will they together fill it. If y>x?

By selling 66 metres cloth, a man loses S.P. of 11 metres. What is the loss percent?

A borrowed Rs.1500 at 4% per annum and Rs.1400 at 5% per annum for the same period. He paid Rs.390 as total interest. Find the time for which he borrowed the sum.

A train passes two bridges of length 400 m and 200 m. in 50 seconds and 30 seconds respectively. The length of the train is-

Inside a square PQRS, ΔQTR is an equilateral triangle. If RT and QS intersect at O, then ∠QOR is equal to-

The L.C.M. of two numbers is 4 times their H.C.F. The sum of L.C.M. and H.C.F is 125. If one of the numbers is 100, then the other number is-

A reduction of 20% in the price of rice enables a man to buy 5 kg more for Rs.100. The price of the rice before reduction was-

If (x +y) = 6 and x² + y² = 20 then find the value of (x - y) ².