Share

Books Shortlist

# A Cylindrical Tub of Radius 12 Cm Contains Water to a Depth of 20 Cm. a Spherical Form Ball is Dropped into the Tub and Thus the Level of Water is Raised by 6.75 Cm. What is the Radius of the Ball? - CBSE Class 9 - Mathematics

ConceptVolume of a Sphere

#### Question

A cylindrical tub of radius 12 cm contains water to a depth of 20 cm. A spherical form ball is dropped into the tub and thus the level of water is raised by 6.75 cm. What is the radius of the ball?

#### Solution

A cylindrical tub of radius = 12cm
Depth = 20cm.
Let r cm be the radius of the ball
Then, volume of ball = volume of water raised

=4/3πr^3 = π r^2h

=4/3πr^3 = π xx(12)^2 xx6.75

⇒  r^3=(144xx6.75xx3)/4

⇒ r^3=729

⇒  r = 9cm

Thus, radius of the ball = 9cm.

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Solution for Mathematics for Class 9 by R D Sharma (2018-19 Session) (2018 to Current)
Chapter 21: Surface Areas and Volume of a Sphere
Ex.21.20 | Q: 31 | Page no. 22
Solution A Cylindrical Tub of Radius 12 Cm Contains Water to a Depth of 20 Cm. a Spherical Form Ball is Dropped into the Tub and Thus the Level of Water is Raised by 6.75 Cm. What is the Radius of the Ball? Concept: Volume of a Sphere.
S