A block of metal 5.5 cm × 10 cm × 3.5 cm is melted and made into coins, each 1.4 cm in diameter and 0.2 cm thick. How many coins are made? Take $\pi = \frac{22}{7}$.

Explanation

1. 01

   Block volume = $5.5 \times 10 \times 3.5 = 192.5$ cm³.

2. 02

   One coin is a short cylinder: $\frac{22}{7} \times 0.7 \times 0.7 \times 0.2 = 0.308$ cm³.

3. 03

   Coins = $192.5 \div 0.308 = 625$.