The total surface area of a closed cylinder is 1232 cm2 and the radius of its base is 7 cm. What is the volume of the cylinder? (Take \(\pi=\frac{22}{7}\))
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 3234 cm3
The total surface area of a cylinder is \(2\pi r(r+h)\): the curved surface plus the two circular ends. With the radius known it gives the height, and then the volume is \(\pi r^2h\).
\(\displaystyle2\pi r=2\times\frac{22}{7}\times7=44\)
\(44(7+h)=1232\), so \(7+h=28\) and \(h=21\) cm
Volume \(\displaystyle=\frac{22}{7}\times7\times7\times21=154\times21=3234\) cm3
