Answer:
ai) 73000 gal/yr
aii) $730 per year
b) 1000 days
Step-by-step explanation:
ai) The water usage per day is ...
(4 showers/day)(10 min/shower)(5 gal/min) = 200 gal/day
Then the usage per year is ...
(200 gal/day)(365 days/yr) = 73,000 gal/yr
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aii) The cost of electricity is the cost of heating half the water usage, so is ...
(0.20 kWh/gal)(1/2)(73,000 gal/yr)($0.10/kWh) = $730/yr
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b) The current daily cost of electricity for heating water is ...
($730/yr)/(365 days/yr) = $2/day
If the cost is cut in half, it will be $1 per day. That means the savings is $1 per day, so it will take 1000 days to recover the $1000 initial cost. (Effectively, the average cost for the first 1000 days is the same as if the water heater had not been replaced.)
Answer:
Step-by-step explanation:
<u>The travel is 2 circumferences:</u>
- 2C = 2*2πr = 4πr = 4*3.14*7 = 87.92 cm
Solve 3x−5 = 9:
Add 5 to both sides, to isolate 3x on the left side: 3x = 5+9 = 14
Solve this for x: x = 14/3
Let x/y be the original fraction.
After decreasing the numerator by 50% and decreasing the denominator by 25%, the fraction is:
(x - 0.5x) / (y - 0.25y) = (0.5x) / (0.75y)
= (2/3)(x/y) = 66 2/3% of x/y
So, the fraction decreased by 33 1/3%.