Question

The volume of a right circular cylinder, 14 cm in height is equal to that of a cube whose edge is 11 cm. The radius of the base of the cylinder is 

(a) 5.2 cm 

(b) 5.5 cm 

(c) 11 cm 

(d) 22 cm

Answer 1

(b) 5.5 cm

Let the radius of the base of the cylinder be r cm. Then,

\(\frac{22}{7}\times{r}^2\times14=(11)^3\)

⇒ r² = \(\frac{11\times11\times11\times7}{22\times14}\) = \(\frac{121}{4}\)

⇒ r = \(\sqrt{\frac{121}{4}}=\frac{11}{2}\) = 5.5 cm.