Mathematics Quiz

The population of a city increases by 5% every year. If its population today is 300,000, what will its population be in 2 years?

• 300,000 · (0.05)

• 300,000 · (1.05)

• 300,000 · (1.05) · (2)

• 300,000 · (1.05)^2

At the beginning of the year, the number of books owned by a library was 10,000. Since then, it has grown by 1% each month. Which expressions represent the number of books, in thousands, owned by the library 5 years later if it continues to grow at that rate?

• 10 · ((1 + 0.01)^12)^5

• 10 · (1 + 0.01)^12^60

• 10 · (1.01)^5

• 10 · (1.01)^60

• 10 · (0.01)^60

For which function does f decrease by 15% every time x increases by 1?

• f(x) = 0.15^x

• f(x) = 0.85^x

• f(x) = 15^x

• f(x) = 85^x

A savings account earns 8% interest each year, compounded quarterly (4 times a year). If a person invests $100 and makes no further deposits or withdrawals, what is the balance in the account after 3 years?

The function c(x) = 72 · (1.04)^x models the cost in dollars, c, of 1 ounce of a certain chemical used in a laboratory. x represents the number of years since 2010. a. Does the cost of the chemical increase or decrease over time, and by what percentage per year does it do so?

The function c(x) = 72 · (1.04)^x models the cost in dollars, c, of 1 ounce of a certain chemical used in a laboratory. x represents the number of years since 2010. b. How much does an ounce of the chemical cost in 2018? Show your reasoning.

Here is a graph that represents f(x) = 5.4321 · 2^x. The coordinates of A are (1, c) and the coordinates of B are (4, d). What is the value of d/c? Explain your reasoning.

When a child is born, her grandfather decides to put $100 in an account that earns interest. He plans to make no other deposits or withdrawals for 18 years. When the child turns 18 years old, the money in the account will be a birthday gift. The grandfather is choosing between two options: - Option 1: An account that grows by 10.5% each year. - Option 2: An account that grows by $20 each year. Which option will result in a better 18th birthday gift? Explain your reasoning.