Practicing Success
The ratio of radius of the base and the height of solid right circular cylinder is 2 : 3. If its volume is 202. 125 cm$^3$, then its total surface area is: (Take $\pi = \frac{22}{7}$) |
168 $cm^2$ 192.5 $cm^2$ 115.5 $cm^2$ 154 $cm^2$ |
192.5 $cm^2$ |
We know that, Total surface area of cylinder = 2πr(r + h) Voulme of cylinder = πr2h We have, Volume = 202.125 cm3 Radius : Height = 2n : 3n According to the question, πr2h = 202.125 = \(\frac{22}{7}\) × 2n × 2n × 3n = 202.125 = n3 = \(\frac{202.125 × 7}{(12 × 22 }\) = n = \(\frac{3.5}{2}\) = n = 1.75 So, the radius of cylinder = 2 × 1.75 = 3.5 Height of cylinder = 3 × 1.75 = 5.25 = Total surface area of cylinder = 2 × \(\frac{22}{7}\) × 3.5 (3.5 + 5.25) = 192.5 |