Download PRECALCULUS NAME_ EXP/LOG APPLICATIONS

PRECALCULUS
EXP/LOG APPLICATIONS
NAME_
DATE___________ PD___
1. Suppose $4000 principal is invested at 6% interest and yields $5353. For
how many years was it invested?
4
ic3--
-
L.t
ibø
2. Suppose $10is invested at 8% interest compounded continuously. When
will the investment be worth $100?
—--------------
.o
-
3. Citizen’s Bank promises to double your money in 8.5 years. Assuming
continuous compounding of interest, what rate of interest must the bank
pay?
4. For a certain strain of bacteria, k is 0.782 when t is measured in hours.
How long will it take 10 bacteria to increase to 500 bacteria?
¶•
=
toe.
—
5. The population of California in 1970 was about 20 million. In 1975, the
population was about 21.8 million. Predict what the population will be in
the year 2006.
fl
Ij
(AUJS-6)
6. Radium-226 decomposes radioactively. Its half-life is 1800 years. Find
the k for the decay formula. If 100 grams was the original amount, how
long before 8 grams are left?
J
_cooc
.
0
k’
•:
-
—
7. The half-life of a lead isotope is 24 years. After 80 years, how much of
1200 gram sample will remain as the original isotope?
.
e.
\\° .o
-2±!
;
8. A new car purchased 10 years ago for $12,000 is worth $1200 today.
Assuming a steady depreciation, what was the yearly rate of depreciation?
r
-)‘J
C
9. Jim and Karen bought a new house 10 years ago for $490,000. The house
is now worth $600,000. Assuming a steady growth rate, what was the
yearly rate of appreciation?
P
t
4
(
10. Electronic equipment valued at $150,000 depreciates 20% per year. After
how many years will the value have depreciated to $15,000?
5cc’
I
‘
i----
.
2\