please help with this too

Answer:
Step-by-step explanation:
Garden roller is in the shape of cylinder.
So, one revolution = Curved surface area of the cylinder
diameter = 70 cm
radius = 70/2 = 35 cm
h = 100 cm
Curved surface area of the cylinder = 2πrh
= [tex]2*\frac{22}{7}*35*100[/tex]
= 22000 square cm
Area covered in 15 revolutions = 15 * 22000
= 330000 square cm
2) Coin
diameter = 22 mm
r = 22/2 = 11 mm
Volume of coin = 66 mm
πr²h = 66
[tex]\frac{22}{7}*11*11*h=66\\\\\\h=\frac{66*7}{11*11*22}\\h=0.17 mm[/tex]