Disha Expert Team Solutions for Exercise 4: PRELIMS (December 2016)

Two pipes A and B can fill a tank in $16$ hours and $12$ hours respectively. The capacity of the tank is $240$ litres. Both the pipes are opened simultaneously and closed after $2$ hours. How much more water(in litres) is needed to fill the tank?

A person covers $32$ km downstream in $240$ minutes and the same person covers $48$ km upstream in $1440$ minutes. Then find the rate of current?

The simple interest on a certain sum at $15\%$ per annum for $5$ years is $₹1500$ more to the simple interest on the same at $12\%$ per annum for the same period. Find the sum?

A dishonest vendor professes to sell fruits at the cost price but he uses a weight of $800$ grams in lieu of $1$ kg weight. Find his percentage gain?

A is $2.5$ times as good workman as B and A is able to finish the work in $50$ days less than B. Find the time in which they can do it working together.

A container contains mixture of milk and water in which milk is $80\%$. $75\%$ of mixture is taken out and $10$ liters water is added, now the concentration of milk in the mixture is $60\%$. Find the quantity of water initially?

Two candles of the same height are lighted at the same time. The first is to be consumed in $5$ hours and the second is in $4$ hours. Assuming that they burn at constant rates, in how many hours their height will be in the ratio $3 : 2.$

Two pipes A and B can fill a tank in $30$ minutes and $45$ minutes respectively. Both pipes are opened. The tank will be filled in just $20$ minutes, if the pipe B is turned off after: