If we are trying to figure out how long it takes for the tank to be fully drained, we just need to divide the volume of the tank by the rate at which oil is being drained.
We know the rate, so we need to find the volume of the tank.
Volume for a cylinder is pi * r^2 * h
Since the diameter is 1.6 ft, the radius is 0.8 ft. We know the length(height) and pi, so our expression for volume is:
3.14 * 0.8^2 * 4.5 = 9.0432 ft^3
Now we just need to divide volume by the drainage rate:
9.0432 / 1.9 = 4.75... ≈ 5 minutes
Hope this helps!
