Math 141, Sem. I, 1998-99 (R.A. Brualdi)
Handout 6 (September 25, 1998)
Topic: Quiz # 2 (10 points per problem)
1. On a trip from Madison to New York City (NYC) you drive via Chicago
and Cleveland. The distance from Madison to Chicago is 150 miles and it
took 3 hours. The distance from Chicago to Cleveland is 400 miles. Your
drive from Cleveland to NYC took 6 hours, and your average speed for
this part of the trip was 70 mph. If your average speed for the whole
trip from Madison to NYC was 60 mph, what was your average speed (to
two decimal places) from Chicago to Cleveland?
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Scratch work - I will not read this.
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Polished solution:
2) [Recall that a watt is a unit of measure for *rate* of consumption of
energy, and that a watt-hour is measure of consumption of energy. A
kilowatt-hour (kwh) is 1000 watt-hours.] Suppose you have 1250 watt hair
dryer, and every morning you use your hair dryer for 10 minutes in order
to dry your hair. Suppose your electric company charges 10 cents per kwh
used. Assuming 30 days in a month, what does it cost you (on your
monthly electric bill) to dry your hair for one month? Answer is to be
given to the nearest penny.
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Scratch work - I will not read this.
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Polished solution: