Question

A roller is 150 cm long has a diameter of 70 cm To level a playground it takes 750 complete
revolutions. Determine the cost of leveling the playground at the rate of 75 cents per metre square​

Answer 1

Answer:

Step-by-step explanation:

→ Diameter of the roller=150cm=70/100=0.7m

→ Therefore it's radius=0.7/2=0.35m

→ Height of the roller=150cm=150/100=1.5m

→ CSA of the roller=CSA of the cylinder

=2πrh

=2×22/7 ×0.35 × 1.5

=44×0.05×1.5

=3.3 sq.m

→ No. of revolutions=750

→ Area of playground=3.3 × 750

=2475 sq.m

→ Rate=75 cents / sq.m

→ Cost of levelling whole playground=2475×75=185625 cents

Answer 2

Area of playground = 750 × CSA of roller

= 750 x 2 x 22x 35 x 150 =

7

750 x 33000 =

= 24750000 cm ^

=2 2475 m ^ 2

Cost of leveling

= 2475 x 0.75

Rs 1856.25