Question

A metallic cylindrical pipe has outer
radius of 3 cm and an inner radius of
2 cm. If the length of the pipe is 70 cm,
then the volume of metal in the pipe, in
cm3, is
(A) 350 a
(B) 630
(C) 280 π
(D) 910​

Answer 1

Given :-

• A metallic cylindrical pipe has outer radius of 3 cm

• An inner radius of metallic pipe is 70cm

• The length of the pipe is 70cm

Solution :-

Here, We have to find the volume of the cylinder.

Inner radius and Outer radius of the cylinder is given.

Therefore,

The inner volume of the pipe = πr^2h

The inner volume of the pipe = π*2 *2*70

The inner volume of the pipe = 280π

Now,

The outer volume of the pipe = πR^2h

The outer volume of the pipe

= π* 3 * 3 * 70

The outer volume of the pipe = 630π

According to the question,

The volume of the metal in the pipe

= Outer Volume - Inner Volume

= 630π - 280π

= 350π

Hence, The volume of the metal in the pipe is 350π $.$

Option A is your answer mate

Answer 2

Answer:

$\huge \mathfrak \green{Given}$

• A metallic cylindrical pipe has outer radius of 3 cm

• An inner radius of metallic pipe is 70cm

• The length of the pipe is 70cm

$\huge \mathfrak \red{Solution}$

Here, We have to find the volume of the cylinder.

Inner radius and Outer radius of the cylinder is given.

Therefore,

The inner volume of the pipe = πr^2h

The inner volume of the pipe = π*2 *2*70

The inner volume of the pipe = 280π

Now,

The outer volume of the pipe = πR^2h

The outer volume of the pipe

= π* 3 * 3 * 70

The outer volume of the pipe = 630π

According to the question,

The volume of the metal in the pipe

= Outer Volume - Inner Volume

= 630π - 280π

= 350π

Hence, The volume of the metal in the pipe is 350π

Therefore option (A) 350 is correct