Question

The bottom of a right cylindrical shaped ve
cylindrical shaped vessel made from metallic sheet
is closed by a cone shaped vessel as shown in
one shaped vessel as shown in the figure. The radius of
the circular base of the cylinder and radius of the circular
of the cylinder and radius of the circular base of the cone
each is equal to 7 cm. If the height of the cylinder is 20 cm and height
of cone is 3 cm, calculate the cost of milk to fill completely this vessel at
the rate of Rs. 20 per litre.
​

Answer 1

Total volume of system

= volume of cylinder + volume of cone

=

$\pi {r}^{2} h \: +( 1 \pi {r}^{2} z) \div 3$

π r² ( h + z/3)

3.14 × 0.07² (0.2 + 0.03/3)

3.14× 0.0049 × (0.21)

0.003231 m³

now

1L = 1000 m³

1 × 0.003231/1000 L = 0.003232

3.23 × 10^( -6) L

now rate of filling 1 L = 20 Rs.

rate of filling 3.23 × 10 ^ (-6) L = 3.23 × 20 × 10^ -6

= 6.26 * 10^ (-5) Rs.