Question

A roller 150 cm long has a diameter of 70 cm. to level a playground it takes 750 complete revolutions. determine the cost of levelling the playground at the rate of 75 paise per sqm

Answer 1

r = 70/2 = 35 cm = 0.35 m
length = 0.15 m
Area covered by roller in 1 revolution = CSA.
= 2×pi×r×h
= 2×22/7×0.35×0.15
= 0.33 m^2
area of playground = area covered by roller in 750 revolutions
0.33 × 750 = 247.5 m^2
cost of levelling the playground = 0.75 × 247.5
= ₹185.625

Answer 2

Answer:

Area of playground = 750 × CSA of roller

= 750 x 2 x 22 x 35 x 150 =

7

750 x 33000 =

=24750000 cm ^

=2 2475 m ^ 2

Cost of leveling

= 2475 x 0.75

Rs 1856.25