We have,
Radius of base = 70 cm
Height of base = 1.4 m = 140 cm
Rate of tin plating = Rs 3.50 per cm2
So,
Total surface area of vessel = Area of outer side of base + Area of inner and outer curved surface
= 2 (πr2 + 2 πrh)
= 2πr (r + 2h)
= 2 × 22/7 × 70 (70 + 2(140))
= 2 × 22/7 × 70 (350)
= 154000 cm2
∴ Cost of tin coating at the rate of Rs 3.50 per 1000 cm2 = 3.50/1000 × 154000
= Rs 539