A factory manufac

The pencil is in shape of cylinder.

Let the radius of base be r cm

Circumference of base = 1.5 cm

2πr = 1.5 cm

[As Circumference of circle is 2πr]

Also, Height, h = 25 cm

As we know,

Curved surface area of cylinder = 2πrh

Where r is base radius and h is height

1 cm = 0.1 dm

1 cm² = 0.01 dm²

37.5 cm² = 0.375 dm²

Cost for coloring 1 dm² = Rs. 0.05

Cost for coloring 0.375 dm² (i.e. 1 pencil) = Rs. 0.01875

Cost for coloring 120000 pencils = 120000 ×0.01875 = Rs. 2250