An office building has 200 occupants, each of whom uses 3.5 gallons of hot water per day for 250 days each year. The temperature of the water as it enters the heater is 55°F (an annual average). The water must be heated to 150°F in order to compensate for a 20°F temperature drop during storage and distribution and still be delivered at the tap at 130°F. The hot water is generated by an oil-fired boiler (using fuel No. 2) with an annual efficiency of 0.60. The cost of fuel is $0.80 per gallon. Determine:

a. The fuel cost savings if the delivery temperature is reduced to 90°F.

b. The fuel cost savings if hot water average usage is reduced by two-thirds.