Question

10. A conical pit of top diameter 3.5 m is 12 m deep. What is its capacity in kilolitres?
(a) 38.5 Kl(b) 48.5 Kl (c) 39.5 Kl (d) 47.5 Kl​

Answer 1

» A conical pit of top diameter 3.5 m is 12 m deep.

Here ..

• Diameter (d) = 3.5 m

So,

Radius (r) = $\dfrac{d}{2}\:=\:\dfrac{3.5}{2}$

=> 1.75 m

• Depth or Height (h) = 12 m

_____________ [ GIVEN ]

• We have to find the capacity of conical pit in kilometers.

_______________________________

› Volume of cone = $\dfrac{1}{3}$πr²h

Put the known values in above formula

=> $\dfrac{1}{3}$ × $\dfrac{22}{7}$ × (1.75)² × 12

=> $\dfrac{22}{7}$ × 1.75 × 1.75 × 4

=> 38.5 m³

In kilometers :-

=> 38.5 × 1 = 38.5 kl

______________________________

38.5 kl is the capacity of conical pit.

Option a) 38.5 kl

____________ [ ANSWER ]

______________________________

Answer 2

d = 3.5 m

r = d/2 = 3.5/2 = 1.75 m

height = 12 m

Volume of cone = 1/3πr²h

1/3 × 22/7 × 1.75 × 1.75 × 12

38.5 m³

In kl

38.5 × 1 = 38.5 kl