Question

30 spherical balls of radius 7 cm each are dropped in a cylindrical tank of radius 49 cm. If the tank is
already filled up to a height of then find the percentage increase in height​

Answer 1

Answer: 200%

Step-by-step explanation:

Given:

No. of spherical balls = 30

Radius of balls = 7 cm

Radius of cylinder = 49 cm

Filled height of cylinder = 20/7 cm

Find: Percentage increase in height

Solution-

Let increase in height of cylinder is h.

Thus, increased volume of cylinder = pi x r x r x h

= pi x 49 x 49 x h cubic cm ........ (1)

Volume of 30 spherical balls = 30 x 4/3 x pi x 7 x 7 x 7 cubic cm ........ (2)

Equating equations 1 and 2, we get

h = 40 / 7

So percentage increase in height = (40/7) x 100 / (20/7) = 200%