Solutions to Chapter 1 Problems
A Note To Instructors: Because of volatile energy prices in today's world, the instructor is encouraged to vary energy
prices in affected problems (e.g. the price of a gallon of gasoline) plus and minus 50 percent and ask students to
determine whether this range of prices changes the recommendation in the problem. This should make for stimulating in-
class discussion of the results.
1-1 (a) 66 million tons per year × (0.05) = 3.3 million tons per year of reduced greenhouse gas
$2.1 billion ÷ 3.3 million tons per year = $636.36 per ton
(b) 3 billion tons per year × (0.02) = 60 million tons per year of reduced greenhouse gas
$2.1 billion/3.3 million tons = $X billion/60 million tons
X = $40.65 billion
,1-2 The primary disadvantage is the installed cost of $8,000 (rather expensive!). A key advantage of
synthetic turf is the annual savings due to lawn maintenance. This may be worth up to $1,000 per year
when periodic lawn mowing, watering, and feeding are avoided.
See what other monetized advantages and disadvantages members of your class can identify. Be
creative!
,1-3 Cost per Watt-hour = $0.90/1.5 Watt-hours = $0.60 per Watt-hour
At a cost of $0.60 per Watt-hour, it would cost (1,000)($0.60 per Watt-hour) = $600 per kilo Watt-hour
for power from a single AAA battery. This is 3,000 times more costly than energy from your local
utility. No wonder we turn off our battery operated devices when we're not using them!
,1-4 At first glance, Tyler’s options seem to be: (1) immediately pay $803 to the owner of the other person’s
car or (2) submit a claim to the insurance company. If Tyler keeps his Nissan for five more years (an
assumption), the cost of option 2 is $500 + ($60 × 2 payments/year) × 5 years = $1,100. This amount is
more than paying $803 out-of-pocket, so Tyler appears to have made the most economical choice.
What we don’t know in this problem is the age and condition of the other person’s car. If we assume it’s
a clunker, another option for Tyler is to offer to buy the other person’s car and fix it himself and then
sell it over the internet. Or Tyler could donate the unrepaired (or repaired) car to his favorite charity.
,1-5 (a) 18,000 miles per year/25 mpg = 720 gallons per year of E20
Savings = 720 gallons per year ($4.40 ‒ $3.73) = $482.4 per year
(b) Gasoline saved = 0.20 (720 gal/yr)(1,000,000 people) = 144 million gallons per year
, 1-6 An economic tradeoff is trading (exchanging) one economic outcome for another. Examples include (a)
whether to ride the bus or drive your car to campus today, (b) whether to pack your lunch or eat at a
local fast food restaurant and (c) whether to carry an umbrella (an inconvenience) or hope for no rain if
you don’t take your umbrella.
A Note To Instructors: Because of volatile energy prices in today's world, the instructor is encouraged to vary energy
prices in affected problems (e.g. the price of a gallon of gasoline) plus and minus 50 percent and ask students to
determine whether this range of prices changes the recommendation in the problem. This should make for stimulating in-
class discussion of the results.
1-1 (a) 66 million tons per year × (0.05) = 3.3 million tons per year of reduced greenhouse gas
$2.1 billion ÷ 3.3 million tons per year = $636.36 per ton
(b) 3 billion tons per year × (0.02) = 60 million tons per year of reduced greenhouse gas
$2.1 billion/3.3 million tons = $X billion/60 million tons
X = $40.65 billion
,1-2 The primary disadvantage is the installed cost of $8,000 (rather expensive!). A key advantage of
synthetic turf is the annual savings due to lawn maintenance. This may be worth up to $1,000 per year
when periodic lawn mowing, watering, and feeding are avoided.
See what other monetized advantages and disadvantages members of your class can identify. Be
creative!
,1-3 Cost per Watt-hour = $0.90/1.5 Watt-hours = $0.60 per Watt-hour
At a cost of $0.60 per Watt-hour, it would cost (1,000)($0.60 per Watt-hour) = $600 per kilo Watt-hour
for power from a single AAA battery. This is 3,000 times more costly than energy from your local
utility. No wonder we turn off our battery operated devices when we're not using them!
,1-4 At first glance, Tyler’s options seem to be: (1) immediately pay $803 to the owner of the other person’s
car or (2) submit a claim to the insurance company. If Tyler keeps his Nissan for five more years (an
assumption), the cost of option 2 is $500 + ($60 × 2 payments/year) × 5 years = $1,100. This amount is
more than paying $803 out-of-pocket, so Tyler appears to have made the most economical choice.
What we don’t know in this problem is the age and condition of the other person’s car. If we assume it’s
a clunker, another option for Tyler is to offer to buy the other person’s car and fix it himself and then
sell it over the internet. Or Tyler could donate the unrepaired (or repaired) car to his favorite charity.
,1-5 (a) 18,000 miles per year/25 mpg = 720 gallons per year of E20
Savings = 720 gallons per year ($4.40 ‒ $3.73) = $482.4 per year
(b) Gasoline saved = 0.20 (720 gal/yr)(1,000,000 people) = 144 million gallons per year
, 1-6 An economic tradeoff is trading (exchanging) one economic outcome for another. Examples include (a)
whether to ride the bus or drive your car to campus today, (b) whether to pack your lunch or eat at a
local fast food restaurant and (c) whether to carry an umbrella (an inconvenience) or hope for no rain if
you don’t take your umbrella.
