A rectangular paper of width 8cm and length 22cm rolled along it width and a cylinder is formed.
On the above Intimation, Solve the question given below
If the outer surface area of cylinder is pointed @ ₹0.5/cm2, then the total cost of painting is
Answer & explanation
Correct answer: option 1
The correct answer is Option 1: 88
Step 1: Identify cylinder dimensions
Rolling along width means:
Height = 8 cm
Circumference = 22 cm
So,
2πr = 22
Using π = 22/7
r = 22 / (2 × 22/7) = 3.5 cm
Step 2: Outer surface area of cylinder
Outer surface area (curved surface area) = 2πrh
= 2 × (22/7) × 3.5 × 8
= 2 × (22/7) × (7/2) × 8
= 176 cm²
Step 3: Cost of painting
Rate = ₹0.5 per cm²
Cost = 176 × 0.5
Cost = ₹88