1. Skeletons were found at a construction site in San
Francisco in 1989. The skeletons had lost 12% of
the amount of carbon-14 that would be found in a living person. In 1989, how old
were the skeletons?
(The decay constant k for carbon-14 is 0.00012)
Losing 12% of carbon-14 means 88% of original amount was still present .
2. The growth model 
approximately describes the United States population, A, in millions,
where t is years after 2003. Answer the three questions be low according to this
population growth
model.
(a) What is the United States growth rate in percent per year? Quick answer – no
calculations
needed. 1.1%
(b) How long (no. of years after 2003) will it take the U.S. population to reach
400 million?
(c) How long (no. of years after 2003) will it take for
the U.S. population double what it was in
2003?
3. A group of APU students take a weekend to go boating on
a river. Their boat goes 7 mph in still
water. They travel downstream to a resting spot in 1.5 hours, and then take 2.0
hours to return to
where they started. How far downstream did they go, and how fast does the river
current flow?
x: one-way distance traveled
r: speed (rate) of river flow
x = (7 + r)1.5 going downstream
x = (7 - r)2.0 going upstream
4. A recent APU business graduate is given $6000 to
invest. She diversified the investment into three
different accounts which earned 4%, 5%, and 8% simple interest after one year .
The total interest
earned for the year was $348. She was a cautious investor; thus, invested $800
more in the account
that earned 5% than the one earning 8%. How much did she invest in each of the
three accounts?
5. Munchies Refreshment Stand sold a hamburger, a bag of
fries, and soda for $6.75. But then Munchies
had to increase the price for fries and sodas. The new price of the fries is 50%
more, and the price of
sodas doubled. Also, before the price increase, fries cost $0.75 more than soda.
What are the current
prices of each of the hamburger, fries, and soda at Munchies?
Question does not contain sufficient information. This was inadvertent on the
instructor’s part.
