The total charge that an automobile battery can supply without being recharged is given in terms of ampere-hours. A typical 12 V battery has a rating of 60 ampere-hours (60 A for 1 h, 30 A for 2 h, and so on). Suppose that you forget to turn off the headlights in your parked automobile. If each of the two head-lights draws 3.8 A, how long will it be before your battery is dead?

7.894 Hours.

Explanation:

Based on information number hours that this battery will last with give load  has mathematical relation of.

with load 60A t =  1h, 30A t = 2h so on and forth.

two head lights draw total current of 2x3.8A = 7.6A.

putting this in above relation gives.

.

That is how long will it be before battery is dead.

the answer would be c

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up