How many litres of water flows out of a pipe having an area of cross section of 5 cm² in one minute, if the speed of water in the pipe is 30 cm/sec?

A cylindrical water tank of diameter 1.4 m and height 2.1 m is being fed by a pipe of diameter 3.5 cm through which water flows at the rate of 2 metre per second. In how much time the tank will be filled?

A rectangular sheet of paper 30 cm × 18 cm be transformed into the curved surface of a right circular cylinder in two ways i.e., either by rolling the paper along its length or by rolling it along its breadth. Find the ratio of the volumes of the two cylinders thus formed.

A solid cylinder has a total surface area of 231 cm². It curved surface area is of the total surface area. Find the volume of the cylinder.

Find the cost of sinking a tube well 280 m deep, having diameter 3 m at the rate of Rs. 3.60 per cubic metre. Find also the cost of cementing its inner curved surface at Rs. 2.50 per square metre.