Question

1.A concrete sphere is to be painted. It is estimated that the first coating costs about 20 pesos persquare meters per worker and the second coating is about 30 pesos per square meters per worker.If the radius of the sphere is 10 meters, how much is the paint job to be accomplished by two workers?

Answer 1

Surface area of sphere=4πr²=400π sq m when r=10m.

Total cost of first and second coat per worker per sq m=20+30=50 pesos.

Total cost of painting per worker=50×400π=20000π pesos=62,832 pesos approx.

Total cost for two workers=125,664 pesos approx.