Question

7. The radii of two cylinders are in the ratio 3 : 2 and their heights are in the ratio 4 : 5. Calculate the ratio
of their curved surface areas.

8. The circumference of the base of a cylinder is 132 cm and its height is 72 cm. Find its lateral surface area.

9. A closed metallic cylindrical box is 1.5 m high and it has a base whose diameter is 70 cm. If the sheet
of metal costs 70 per sq. m, find the cost of the material used in the box.

10. How much metal sheet is required to make an open cylindrical tank of radius 4.2 m and height 15 m.
(With Explanation)​

Answer 1

8) base = 5x 50m&height = 2x = 20 m

CSA=2πrh=(2πr)×h=132×72

=9504cm2.