Question

a circular well of depth 7 m radius 1.5 m is dug. Calculate the cost of cementing the inner surface at the rate of rupee .50 per m square

Answer 1

Answer: Radius of well= 1.5m

Height of well= 7m

Inner surface area=2πrh

=2×22/7×1.5×7

= 44×1.5

=66 cm sq.

Cost of cementing = 0.50×66

= ₹33

Answer 2

height of the well =7m
radius of the well =1.5m
surface area of the inner surface=Curved surface area
=
$2\pi {r}h$
=
$2 \times \frac{22}{7} \times 1.5 \times 7$
=66 m sq.
total cost=Rs 0.50 X 66
=Rs33