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 that 

r = 70cm, h =1.4m =140cm 

∴Area to be tin coated=`2(2pirh+pir^2)=2pir(2h+r)`

=`2xx22/7xx70(280+70)`  

`=154000cm^2` 

Required cost =`(154000xx3.50)/1000=Rs.539.`