Q : 9 Find (ii) how much steel was actually used, if of the steel actually used was wasted in making the tank.
Given, a closed cylindrical petrol tank.
The diameter of the tank =
Height of the tank =
Now, Total surface area of the tank =
Now, let of steel sheet be actually used in making the tank
Since of steel was wasted, the left of the total steel sheet was used to made the tank.
The total surface area of the tank =
Therefore, of steel was actually used in making the tank.