AFM-ExpGrowth/Decay/compound interest quiz review

An adult takes 400 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How long until there is about 51.2mg left in her system?

• 10 hours

• 6 hours

• 3 hours

• 8 hours

You buy a new computer for $2100. The computer decreases by 50% annually. When will the computer have a value of less than $150?

• between 1 and 2 years

• more than 5 years

• less than a year

• between 3 and 4 years

The foundation of your house has about 1,200 termites. The termites grow at a rate of about 2.4% per day. How long until the number of termites triples?

• 46 to 47 years

• 23 to 24 years

• between 46 to 47 days

• 19 to 20 dasys

A painting's value increases by 9% each year. At the end of five years, it is worth $2154.07. What was the original value?

• $3314.30

• $2500

• $1000

• $1400

Suppose you deposit $3000 in a savings account that pays interest at an annual rate of 4%. If no other money is added or withdrawn from the account, how much interest will you make after 10 years?

• $3122.18

• $4994.50

• $1440.73

• $86,776.40

Daniel’s Print Shop purchased a new printer for $35,000. Each year it depreciates at a rate of 5%. How many years until the value is only $23,220?

• 10

• 6

• 8

• 12

Olivia would like to buy some new furniture for her home. She decides to buy the furniture on credit with 9.5% interest compounded quarterly. If she spent $7,400, how much total interest will she have paid after 8 years.

• $15,415.94

• $8,283.28

• $15,927.56

• $16,109.05

Domenic is not feeling very well. On Monday, he started out with 1,000 bacteria. They are doubling every day! If this continues, how many bacteria will he have by Friday?

• 1000

• 5000

• 32000

• 64000

Eric is getting over a bacteria infection. He had 100,000 bacteria on Monday. If he takes his medicine, the bacteria decrease by .5 every day. How many bacteria will be left by Friday?

• 100,000

• 50,000

• none

• 3125

Emily's parents put $1,500 in her bank account for college tuition. At an interest rate of 8.25% compounded semi-annually, how many years until the balance is $6,427.94?

• 14

• 10

• 20

• 18