Mensurationmedium · Past Paper
Find the total surface area of a hollow cylinder open at both ends, if its length is 12 cm, external radius is 4 cm and thickness is 1 cm.
A168π sq. cm
B182π sq. cm
C154π sq. cm
D196π sq. cm
✓ Correct Answer: B — 182π sq. cm
R=4, r=3, h=12. TSA = 2πRh + 2πrh + 2π(R²-r²) = 2π(4*12) + 2π(3*12) + 2π(16-9) = 96π + 72π + 14π = 182π sq. cm.
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