The slant height of a cone is 5cm and the radius of its base is 3cm. Find, correct to the nearest whole number, the volume of the cone. ( Take \(\pi = \frac{22}{7}\))

A.

48cm3

B.

47cm3

C.

38cm3

D.

12cm3

Correct answer is C

Volume of a cone = \(\frac{1}{3} \pi r^2h\)

h2 = 52 = 32

= 25 - 9 = 16

h = \(\sqrt{16}\)

h = 4cm

v = \(\frac{1}{3} \times \frac{22}{7} \times 3^2 \times 4\)

\(\frac{1}{3} \times \frac{22}{7} \times 9 \times 4\)

= \(\frac{22 \times 3 \times 4}{7}\)

= 37.7cm3

= 38cm3