Question

The height of a right circular cylinder is three times the radius of the base.If the height were four times the radius,the volume would be 1078 CC more than it was previously.Find the radius of the base.

Answer 1

7 is the answer
Hope It Will Help You

Answer 2

Answer:

The radius off the base is 7 cm.    

Step-by-step explanation:

Given : The height of a right circular cylinder is three times the radius of the base. If the height were four times the radius,the volume would be 1078 cm more than it was previously.

To Find : The radius of the base?

Solution :

Let the radius of the base be 'r'.

The height of a right circular cylinder is three times the radius of the base.

i.e. Height, h=3r

The volume of the cylinder is

$V=\pi r^2h$

$V=\pi r^2\times 3r$

$V=3\pi r^3$

If the height were four times the radius,

i.e. h=4r

The volume of the cylinder is

$V_n=\pi r^2h$

$V_n=\pi r^2\times 4r$

$V_n=4\pi r^3$

The volume would be 1078  more than it was previously.

i.e. $V_n-V=1078$

$4\pi r^3-3\pi r^3=1078$

$\pi r^3=1078$

$r^3=1078\times\frac{7}{22}$

$r^3=343$

$r^3=7^3$

$r=7$

Therefore, The radius off the base is 7 cm.