Maths 3
1. In a cylinder , if radius is halved and height is doubled , the volume will be : ( b ) doubled ( c ) halved ( a ) same ( d ) four times 2. Find the volume of a right circular cylinder which has a height of 21 cm and the base radius of 5 cm . Also find the curved surface area of the cylinder . 3 Find the radius of a right circular cylinder whose volume is 3080 cm and height is 20 cm . 4. A cylindrical water tank has a capacity of 2156 kf and diameter of its base 14 m . Find the depth of the tank . 5. How many cubic meters of earth must be dug out to s²ink a well 7 m deep and radius 5 m ? Find the cost of plastering its lateral surface area at the rate of 15 per m 6. The volume of earth taken out on digging a cylindrical well is 1540 m² Find the depth of the tank if its base has radius 350 cm . The thickness of a hollow metallic cylinder is 2 cm . It is 70 cm long and its outer diameter is 28 cm . Find the volume of the metal required to make the cylinder , assuming it is open at both ends . What is the weight of cylinder if the metal weighs 8 g per cm " ?