Question

61. By melting of a solid cuboid of length 16cm, breadth 11cm, height 10cm,
how many solid coins of 0.2cm thick and 2cm diameter can be formed?
(1) 2200
(2) 2400
(3) 2600
(4) 2800​

Answer 1

(2) 2400.✌✌.............

Answer 2

Number of solid coins are 2800

Step-by-step explanation:

Volume of cuboid = n Volume of solid coins

The solid coins are of cylinder-shaped.

Volume of the solid cuboid = (16$\times$11$\times$10) $cm^{3}$ = 1760 $cm^{3}$

Let r be the radius of the coin

r= $\frac{d}{2}$ =$\frac{2}{2}$ =1 cm

Volume of the solid coins = $\pi r^{2} h$ = 3.14 $\times$ 1 $\times$1 $\times$ 0.2 $cm^{3}$ = 0.628 $cm^{3}$

Volume of cuboid = n Volume of solid coins

Therefore,

1760 = 0.628 n

⇒ n ≈ 2800

Number of solid coins are 2800