A 35 cm high bucket in the form of a frustum is full of water. Radii of its lower and upper ends are 12 cm and 18 cm, respectively . If water from this bucket is poured in a cylindrical drum, whose base radius is 20 cm, then what will be the hieght of water ( in cm) in the drum ?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 19.95
Solution :
According to question
Volume of frustum = Volume of cylinder
1/3 πH (R2 +Rr+r2 ) = π × r2 × h
1/3 × 22/7 × 35 (144 + 216 + 324) = 22/7 × 400 × h
35/3 × 684 = 400 × h
h = (35 × 684)/1200
h = 19.95 cm