Question

) Find the number of coins, 3 cm., in diameter and 0.4 cm., thick, to be melted to form a right
circular cylinder of height 20 cm., and diameter 9 cm.​

Answer 1

Answer:

Let n be the number of 1.5 cm diameter coins required to form a right circular cylinder of height 10 cm and diameter 4.5 cm.

Now,

Volume of right circular cylinder =n× volume of 1.5 cm diameter coin.

Therefore,

n=

π(

2

1.5

)

2

×

10

2

π(

2

4.5

)

2

×10

=

20×20

45×45

×

15×15×2

10×20×20×10

=9×10×5

=450