A rectangular paper of width 8 cm and length 22 cm is rolled along its width and a cylinder is formed.
On the above information, solve the question given below
If the outer surface area of the cylinder is painted @ ₹0.5/cm2, then the total cost of painting is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → ₹88
The outer surface of the rolled cylinder is the sheet itself: its curved surface area \(2\pi rh\) is the circumference (22 cm) times the height (8 cm), which is the area of the rectangle. The cylinder has no ends, so nothing else is painted.
Outer surface area \(=22\times8=176\) cm2
Cost of painting \(=176\times0.5=\) ₹88