Question

1. A cone of height 8 m has a curved surface area 188.4 square metres. Find its volume.
2. Find the volume and curved surface area of a right circular cylinder of height 21 cm and
base radius 5 cm.
3. The surface area of a sphere is 394.24 m2
. Find its radius and volume.
7. The mean of the following data is 21.6. Find p.
Xi: 6 12 18 24 30 36
Fi : 5 4 p 6 4 6

Answer 1

1.h=8 m,c.s.a=188.4 square meters.
c.s.a of cone =22/7xrxl
188.4=176/7xl
l=188.4x7/176
l=7.49m
volume of cone =1/3x22/7x8x8xh
where h=root of r square -l square
h=2.8m
volume=1/3x22/7x8x8x2.8
volume=563.2meter cube

Answer 2

2. volume=πr×rh
=22÷7×5×5×21
=22×25×3
=550×3
=1650 cubic cm
C.S.A=2πrh
=2×22÷7×55×21
=220×3
=660 sq. cm