A hollow cylinder with outer radius 4 cm and height 2 cm is made up of 1 cm thick metal sheet. What is the volume of metal used? (Take π = 22/7)
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 44 cm3
Let R be outer radius and r be the inner radius of hollow cylinder
R = 4cm , r = 4 - 1 = 3cm ,h = 2cm
volume of hollow cylinder = π(R2 - r2)h
volume of hollow cylinder =(22/7) × (42 - 32) × 2
volume of hollow cylinder = 22 × 7 × 2/7
volume of hollow cylinder = 22 × 2 = 44cm3
Short Trick:
Answer will be divisible by 11.
Only option 3 divisible by 11.