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MATH 168 Module 5 Practice Test
Write your answers in the spaces provided.
All questions are of equal value.
1. Simplify
(6u 6 v10 ) 4
8 13 3
(12u v )
.
2. Solve the equation 8  10n  28 , giving your answer
correct to 4 significant figures.
3. Solve the equation 12t 9  20 correct to 3 decimal places.
4. An obsessive gambler borrows $3,000 from a loan shark
at an interest rate of 19% per month. What is the
equivalent annual interest rate?
5. A radio-active isotope has a half-life of 6 hours. If you
start with 512mg of this material, how much will remain 3
days later?
6. Solve the equation
4t 3  12 .
7. If $
is invested for
years at 4.97% interest,
payable annually, how much will be available when the
investment matures?
8. Oil-drilling equipment is purchased for $12.6 million. For
the purposes of annual accounts, its value is depreciated
by 15.7% each year. What will its nominal value be after
8 years?
9. Write the identity log (625)  4 in index form.
5
10. I invest $35,500in shares. Over 5 years, it grows to
$74,800.What is the annual rate of return?
11. If $8,750 is invested at an annual rate of return of 5.9%,
how long will it take this investment to grow to be
worth $20,000?
12. The number of bacteria in a culture increases by 15%
every 2 hours. If there is an estimated 60,000 now, how
long ago was there just one bacterium?
13. I invest $30,000 in shares. I make a 28% profit in my
first year, and a 22% loss in my second year. I then cash
out my position. How much money will I have?
14. The value of a company has been growing by 25% per
year. Its value is now $64 million. When was it valued at
$30 million?
15. Evaluate log (9999) correct to 4 significant figures.
9
Formulae
Growth/Decay
, where
Change of base
initial ‘amount’