A 90-V Battery Costs $1

Multiple Choice

A 9.0-V battery costs $1.49 and will run a portable CD player for 6.0 hours before running down and needing to be replaced.If this battery supplies a current of 25 mA to the player,what is the cost of the energy provided by the battery in dollars per kWh?

A) $11/kWh
B) $110/kWh
C) $1100/kWh
D) $11,000/kWh