Question

The length of outer and inner diameter of hollow right circular cylinder are 16cm. and 12cm. respectively. Height of cylinder is 36 cm. Let us calculate how many solid cylinders of 2cm. radius and 6cm. length may be obtained by melting this cylinder.​

Answer 1

The outer diameter = 16 cm <br>

The outer radius

<br> The inner diameter = 12 cm <br>

the inner radius

. <br> Height of the cylinder

. <br> So, the volume of the materials of the hollow cylinder <br>

. <br> The radius of small cylinders to be made

and their lengths = 6 cm each. <br>

The volume of each small cylinders to be made

<br> So the required number of small cylinders

. <br> Hence the required number of cylinders to be made is equal to 42. <br> [ N.B. : If the outer and inner radius ( not diameter) be 16 cm and 12 cm respectively, then the number of cylinders is 168. ]

Answer 2

Answer:

42 small cylinders.

Step-by-step explanation:

The outer diameter = 16cm

... The outer radius 16/2 cm = 8cm

The inner diameter = 12cm

... The inner radius = 12/2 cm = 6 cm

Height of the cylinder = 36cm

So, the volume of the materials of the hollow cylinder = 22/7 {(8)² - (6)²} × 36cc = 22/7 × 28 × 36cc

The radius of small cylinders to be made = 2cm and = 6cm each.

... The volume of each small cylinders to be made = 22/7 × (2)² × 6cc = 22/7 × 4 × 6cc

So, the required number of small cylinders

$= \frac{ \frac{22}{7} \times 28 \times 36}{ \frac{22}{7} \times 4 \times 6} = 42$

Hence, the required number of small cylinders is 42.