Chapter: Mensuration· Mathematics Part 2 (Geometry)
Answer: 1600 coins
Cylinder: height = 0.2 m = 20 cm, radius R = 8.8 ÷ 2 = 4.4 cm.
Each coin is a small cylinder: radius r = 2.2 ÷ 2 = 1.1 cm, thickness t = 0.2 cm.
Number of coins \(= \dfrac{\pi R^2 H}{\pi r^2 t} = \dfrac{4.4 \times 4.4 \times 20}{1.1 \times 1.1 \times 0.2}\)
\(= \left(\dfrac{4.4}{1.1}\right)^2 \times \dfrac{20}{0.2} = 4^2 \times 100 = 16 \times 100 = 1600\).