Question

A cylindrical vessel, without lid, has to be tin-coated on its both sides. If the radius of the base is 70 cm and its height is 1.4 m, calculate the cost of tin-coating at the rate of Rs. 3.50 per 1000 cm².

Answer 1

Given,

Radius of base = 70 cm

Height of base = 1.4 m = 140 cm

So,

Area = 2πr(h + \(\frac{r}{2}\)) = 2 x \(\frac{22}{7}\) x 70(140 + \(\frac{70}{2}\)) = 2 x 22 x 10(175) cm²

Tin coating must be done on both side so Area = 2(2 x 22 x 10(175) cm²

∴ Cost of tin coating at rate Rs.3.50 per 1000 cm² = \(\frac{[2\times 2\times 22\times 10\times 175]}{1000}\) = \(\frac{5390}{10}\) = Rs. 539