Question

4. If the radius and height of a cone are both increased by 100%, then its volume is
increased by
a. 400%
b. 300%
c. 200%
d. 100%

Answer 1

Answer:

If the radius and height of a cone are both increased by 100% , then its volume is increased by:

old radius of cone = r

old height of cone = h

They increased by 100%

So,

new radius = 2r

new height - 2h

∴ new volume =

3

π

(2r)

2

(2h)

=8×

3

π

r

2

h

New volume = 8 × old volume ... (1)

change in volume =

oldvolume

newvolume−oldvolume

×100

From (1)

change in volume =(

1

8−1

)×100

=700%

solution

Answer verified by Toppr