Harkamal purchased 8 Kgs. of grapes at the rate of Rs. 70/- per Kg. and 9 Kgs. of mangoes at the rate of Rs. 55/-per kg. How much amount did he pay to the shopkeeper?

The cost of 15 kgs. of sugar is Rs. 255, the cost of 17 kgs. of tea is Rs. 1615 and the cost of 22kgs. of rice is Rs. 572. What is the total cost of 18 kgs.of sugar, 21 kgs. of tea and 27 kgs. Of rice?

A and B are two taps which can fill a tank individually in 10 minutes and 20 minutes respectively. However, there is a leakage at the bottom which can empty a filled tank in 40 minutes. If the tank is empty initially, how much time will both the taps take to fill the tank (leakage is still there) ?