The sum of the radius of the base and the height of a closed solid cylinder is 12.5 cm. If the total surface area of the cylinder is 275 cm2 , then its radius is:
(Take $π =\frac{22}{7}$)
Answer & explanation
Correct answer: option 1
We know that,
Total surface area of a closed cylinder = 2πR (H + R)
Given,
Radius + Height = 12.5 cm
Total surface area of cylinder = 275 cm2
So,
= 275 = 2 × \(\frac{22}{7}\)× R × (12.5)
= R = (275 × 7 × 10) × \(\frac{1}{2 × 22 × 125 }\)
= R = 3.5