Multiple choice

A solid cuboid has dimensions 14 cm × 18 cm × 24 cm. A hemisphere of radius 3.5 cm is cut from the centre of each face of cuboid. What is the total surface area (in cm2) of the remaining solid?

  1. 1902

  2. 1809

  3. 1706

  4. 2271
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Surface area of cuboid = 2(14*18 + 18*24 + 24*14) = 2(252 + 432 + 336) = 2040. Each hemisphere removed subtracts pi*r^2 from the surface but adds 2*pi*r^2 (the bowl surface), net change = +pi*r^2 per face. 6 faces, so 6 * pi * (3.5)^2 = 6 * (22/7) * 12.25 = 231. Total area = 2040 + 231 = 2271.

Keep practicing — related questions