the volume of frustum of a cone whose height is 42cm and radii of top and bottom circular ends are 10cm and 15cm respectively is
Answers
Given as :
A bucket, is in the form of frustum of a cone
The height of the cone = h = 42 cm
The radius of upper end = = 10 cm
The radius of lower end = = 30 cm
To Find :
The quantity of milk hold in the frustum
The total amount of money earn after sale of milk at Rs 40 per liter
Solution :
For frustum
Volume = × π × height [ + + ]
= × 3.14 × 42 cm × [ + + × 30 cm ]
= 65.64 cm × [ 100 cm² + 900 cm² + 300 cm² ]
= 65.64 cm × 1300 cm²
= 85332 cubic cm
So, The volume of frustum bucket = 85332 cubic cm
∵ 1 liter = 1000 cubic cm
or, 1000 cubic cm = 1 liter
So, 1 cubic cm = liter
∴ 85332 cubic cm = = × 85332 liter = 85.332 liters
So, The quantity of milk that hold in the frustum = 85.3 liters
Again
∵ The cost of 1 liter of milk = Rs 40
∴ The cost of 85.3 liters of milk = Rs 40 × 85.3 = Rs 3412
Hence,
The quantity of milk that hold in the frustum is 85.3 liters
The cost of 85.3 liters of milk is Rs 3412 Answer