Question

The radius and height of a cylinder are in the ratio 5:7 and its volume is 550 cm${}^3$ Find its radius

• A. 4 cm
• B. 6 cm
• C. 5 cm
• D. $\frac{5}{2}cm$

Answer 1

Answer: (C)

Let r= 5x and h=7x
Volume = $=\pi r^{2}h=\frac{22}{7}\times 25x^2\times 7x=550$
or $x^3=\frac{550\times 7}{22\times 25\times 7}=\frac{550}{550}=1orx=1$
Hence the radius of the cylinder is 5 $\times$ 1 cm = 5cm