Self-study
After replacing his old gas water heater with a new, pilotless, gas water heater that is rated as highly efficient, Jimmy's gas bills increased.
2.
Each of the following, if true, contributes to an explanation of the increase mentioned above EXCEPT:
a
The new water heater uses a smaller percentage of the gas used by Jimmy's household than did the old one.
(A) doesn’t help explain why the new water heater is costing Jimmy more for gas. If the new water heater is using a smaller percentage of the house’s gas than the old water heater did, we’d expect Jimmy to spend less on gas for the new water heater.
b
Shortly after the new water heater was installed, Jimmy's uncle came to live with him, doubling the size of the household.
The number of people using gas in the household doubling after installing the new water heater would likely lead to an increase in the amount Jimmy is spending on gas.
c
After having done his laundry at a laundromat, Jimmy bought and started using a gas dryer when he replaced his water heater.
If Jimmy started using a gas dryer in his home when he previously didn’t have a dryer, it could help explain why he’s now spending more on gas even though his new water heater is more gas-efficient than his old one.
d
Jimmy's utility company raised the rates for gas consumption following installation of the new water heater.
Higher rates for gas could lead to Jimmy paying more for gas even if his new water heater is more gas-efficient than his old water heater.
e
Unusually cold weather following installation of the new water heater resulted in heavy gas usage.
If Jimmy had to use an unusually high amount of gas because of cold weather, it could have led to him spending more on gas for his new water heater even though it’s more gas-efficient than his old water heater.