Answer:
about 13 cans of paint
Explanation:
To find how many cans the farmer needs to buy, you need to know the surface area of both the cone and cylinder.
The way to find the SA of the cone would be area = 3.14 x r^2 + 3.14 x r x sqrt(r^2 + h^2).
SA= 1976.0617791 m^2.
The way to find SA of the cylinder under the cone would be 3.14 x d x (d / 2 + h).
A = 3097.6103564 m^2
Then you have to add 1976.0617791+3097.6103564 which gives you 5,073.8. (5,073 being total surface area of the silo)
Next divide that by 400.
5,073.8/400 = 12.7
He would need to buy about 13 cans of paint to be able to paint the entire silo.