Question

FInd the cost of painting15 cylinder pillar of a building at ₹2.50per square metre .if the daimeter and height of each pillar are 48 cm and 7 meter respectively

Answer 1

Diameter of the cylindrical pillar=48cm
we know that
radius is half of the diameter
therefore radius of the cylindrical pillar is 24 cm .=0.24m

HEIGHT OF THE PILLAR=7m

THE 15 cylindrical pillars are to be painted .
however only their curved surface areas will be painted .

we know that ,
$curved \: surface \: area = 2\pi rh$
=2×22/7×0.24×7
=2×22×0.24
=44×0.24
=10.56sq.m

curved surface area of 15 cylinder pillars :
15(10.56)=158.4sq.cm

cost of painting 15 cylindrical pillars at the rate of ₹2.50 per sq. m
=158.4×2.50₹
=₹396.

FINAL ANSWER:
The cost of painting 15 cylindrical pillars is ₹396

HOPE THIS HELPS YOU