Question

3. A metal strip having sides 11x7x 5cms is melted and minted into coins, each of diameter 1.4cm and thickness is 0.08cm. How many coins can be minted?​

Answer 1

Answer:

Volume of metal strip= 11×7×5 cc cm -(1)

volume of coin= 3.14 × (1.4/2)^2 ×0.08 cc cm

let 'n' be the total number of coins, so

total volume of coins = 3.14×(1.4/2)^2× 0.08×n -(2)

now (1) & (2) should be equal,

3.14×(1.4/2)^2× 0.08×n =

11×7×5

or, n= (11×7×5)/3.14×(1.4/2)^2× 0.08

or, n= 3126 ( approx)

hence, 3126 coins can be minted