. How are mineral deposits formed around vents?

When hot, metal-laden water spews from vents and mixes with the cold ocean, the metals precipitate. Large piles of sulfide accumulate on the seafloor and are eventually buried by sediments, modified by heat and pressure in the crust, and uplifted. Some are exposed on land when erosion removes the overlying rocks.

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.