A closed cylindrical tank of radius 1.5 m and height 3 m is made from a sheet of metal, how much sheet of metal is required to do it?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 42.42 m2.
The total surface area (SA) of a closed cylindrical tank = 2πr2 + 2πrh
here, r = radius
SA = 2πr2 + 2πrh
⇒ SA = 2πr(r + h)
⇒ SA = 2 × 22/7 × 1.5(1.5 + 3)
⇒ SA = 44/7 × 1.5 × 4.5
⇒ SA = 44/7 × 6.75
⇒ SA = 297/7 = 42.42 m2