The upper and lower part radius of a bucket is 30 cm. and 20 cm. Its height is 60 cm. How much w

M4maths Previous Puzzles

10 Feb 2010 How much water in the Bucket?

The upper and lower part radius of a bucket is 30 cm. and 20 cm. Its height is 60 cm.
How much water can be filled in the bucket ?
It is given that: 1 litre = 1000 cm.^3

OPtion

(1) 100 litre
(2) 130 litre
(3) 120 litre
(4) 90 litre
(5) 105 litre
(6) 125 litre
(7) 150 litre
(8) 95 litre
(9) 200 litre
(10) 175 litre

Solution

On increasing the slant sides of the bucket, a cone can be obtained, whose height is obtained by the formula h/(h-60) = 30/20
On solving h = 180
Think that: two cones can be formed by increasing the slant height, their radii and heights are 30 cm.,
20 cm. and 180 cm., 120 cm.
Volume of the cone is πr^2/3
Therefore volume of the bucket is π(30)^2*180/3 – π(20)^2*120/3
= 38000π cm.^3
= 38π litre

Correct Option: 3 Best Solution (5)

Dolly   14 years AGO

vol = 1/3 * pi* 60 ( 30^2+20^2+ 30*20)/1000 = 38*22/7 = 119.42 litres

Like? Yes (1) | No   

Bimal   14 years AGO

Vol of bucket = (1/3)*pi*h(R1^2+R1*R2+R2^2).

so vol in this case = (1/3)*pi*60 ( 900+400+600)/1000 = 38 Pi litres = 120 litres

Like? Yes (1) | No   

Bawa   14 years AGO

vol = (pi/3)* 60*( 900+400+600) /1000 = 120 litres ( approx)

Like? Yes (1) | No   

Meena   14 years AGO

using formula for volume of frustum, we get vol of backet as approx. 120 litres .

Like? Yes (1) | No   

sujit   14 years AGO

Volume of frustum
V = pi*h/3 (R^2 + r^2 + Rr)

V= volume
pi=3.141592654
h=height of the frustum
R=Bigger area
r=smaller area

Like? Yes (1) | No