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
The radius of the cylinder is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \(\frac{7}{2}\) cm
Rolling the sheet along its width makes the 22 cm length go round the circle, so 22 cm is the circumference of the cylinder, \(2\pi r\); the 8 cm width becomes the height.
Circumference (the 22 cm length): \(2\pi r=22\)
Taking \(\pi=\frac{22}{7}\): \(\displaystyle 2\times\frac{22}{7}\times r=22\)
\(\displaystyle r=\frac{7}{2}\) cm