Question

A factory manufactures 120,000 pencils daily The pencils are cylindrical in shape each of length 25cm and circumference of base is 1.5cm. Determine the cost of colouring the curved surfaces of the pencils manufatured in one day at Rs.0.05 per $d{m}^2$.

Answer 1

The surface area of one pencil = 25 × 1.5 = 37.5 cm²
The total surface area of pencils made in a day = 37.5 × 120000
= 4500000cm²
= 45,000dm² [Note: 1dm² = 100cm²]
The cost of colours = 45,000 x 0.05 = Rs. 2,250