Question

a closed metallic cylinder has its base of daimeter 56cm and it is 2.25 m high find the cost of the metal used to make it if it costs ₹80 per square metre

Answer 1

Please refer the above photograph for the used process.
Actually i have forgot to put the decimal in the total surface area
TSA will be4. 4528
And, ultimately
The cost will be rs. 352.24

Sorry for the mistake.

Hope this will be helping you.

Answer 2

In the question I've assumed that the cylinder is hollow made of a metal with negligible thickness...
Remember: 1m^2=10000cm^2
Check the pic...