# Exponential Functions II Worksheet

Exponential Functions II Worksheet
• Page 1
1.
What is the percent increase in the growth of a tree if the initial height of the tree is one foot and the height after one year is 1.3 feet?
 a. 50% b. 40% c. 20% d. 30%

2.
Rents in a particular area are increasing by 2% every year. Predict the rent of the apartment after 2 years, if its rent is $500 per month now?  a.$521.2 b. $531.2 c.$530.2 d. $520.2 #### Answer: (d) Correct answer : (4) 3. Which of the following models is an exponential decay model?  a. $y$ = 10 + 3$t$ b. $y$ = $\frac{1}{3}$$t$2 c. $y$ = 8($\frac{3}{7}$)$t$ d. $y$ = 12($\frac{4}{3}$)$t$ #### Answer: (c) Correct answer : (3) 4. There are 15 lions in a zoo. What will be their population after 4 years, if the population doubles each year?  a. 340 lions b. 240 lions c. 290 lions d. 60 lions #### Answer: (b) Correct answer : (2) 5. The price of gold is$300 per 10 grams in the month of January. It loses its value at a rate of 5% per month. Find the cost of the 10 grams gold in the month of August.
 a. $200 b.$110 c. $210 d.$190

6.
A company purchased machinery in the year 1990 for $25,000. Its cost depreciates at a rate of 5% per year. Identify an exponential decay model to represent the cost of the machinery.  a. $y$ = 25000(0.85)$t$ b. $y$ = 25100(0.95)$t$ c. $y$ = 25000(0.95)$t$ d. $y$ = 24900(0.95)$t$ #### Answer: (c) Correct answer : (3) 7. Frank started a business in the year 1991. He got$27,000 profit in the first year. Each year his profit decreased by 3%. Identify an exponential decay model to represent his decreasing annual profit in the business.
 a. $y$ = 27000(0.87)$t$ b. $y$ = 26999(0.97)$t$ c. $y$ = 27000(0.97)$t$ d. $y$ = 27001(1.07)$t$

The profit made by a software company in 1992 was $448 million. Identify an expression to represent the profit made by the company after $n$ years, if the profit is growing exponentially at a rate of 0.4% per year?  a. 448(1.004)$n$ b. 448(1 - 0.004)$n$ c. 448(0.004)$n$ d. 448(1 + 1.004)$n$ #### Answer: (a) Correct answer : (1) 9. The average length of a person's hair at birth is 0.36 inches. The length of the hair increases by about 10% each day during the first six weeks. Choose a model that represents the average length of the hair during the first six weeks.  a. $y$ = 0.36(11)$t$ b. $y$ = 0.36(1.1)$t$ c. $y$ = 0.36(6$t$) d. $y$ = 0.36(0.9)$t$ #### Answer: (b) Correct answer : (2) 10. A bank pays 3% interest compounded yearly on a deposit of$600. What will be the balance in the account after 4 years?
 a. $575 b.$1350 c. $675 d.$775