# Time + exponential function - math problems

#### Number of problems found: 50

• Car value
The car loses value 15% every year. Determine a time (in years) when the price will be halved.
• Suppose 2
Suppose that the half-life of a substance is 250 years. If there were initially 100 g of the substance, a. Give an exponential model for the situation b. How much will remain after 500 years?
• Population
What is the population of the city with 3% annual growth, if in 10 years the city will have 60,000 residents?
• Two years
Roy deposited 50,000.00 into his account paying 4% annual interest compounded semi annually. How much is the interest after 2 years?
• Demographics
The population grew in the city in 10 years from 30000 to 34000. What is the average annual percentage increase of population?
• If you 3
If you deposit \$4500 at 5% annual interest compound quarterly, how much money will be in the account after 10 years?
• How much 2
How much money would you need to deposit today at 5% annual interest compounded monthly to have \$2000 in the account after 9 years?
• Future value
Suppose you invested \$1000 per quarter over a 15 years period. If money earns an anual rate of 6.5% compounded quarterly, how much would be available at the end of the time period? How much is the interest earn?
• RC time constant
You introduced 1 Coulomb worth of electrons into the inner volume of a dielectric material with ϵr=6. 30 minutes later, you found that only 36.79% of the electrons were in the inner volume. Determine the conductivity σ of the dielectric material.
• Deposit 3
After a year had Martin on bank account € 2028. What was the interest rate when the initial deposit was € 1879?
• Deposit
If you deposit 719 euros the beginning of each year, how much money we have at 1.3% (compound) interest after 9 years?
• Half life
Determine the half life of bismuth, when bismuth weight from the original weight of 32 g was only 2 grams in 242 minutes.
• Population
The town has 65,000 inhabitants. 40 years ago, there were 157,000. How many people will live in a city in 10 years if the population's average rate is as in previous years?
• Slow saving in banks
How long will it take to save € 9,000 by depositing € 200 at the beginning of each year at 2% interest?
• If you 4
If you deposit \$2500 in an account paying 11% annual interest compounded quarterly, how long until there is the \$4500 in the account?
• If you 2
If you deposit \$4000 into an account paying 9% annual interest compounded monthly, how long until there is \$10000 in the account?
• The half life
The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 145 grams of a radioactive isotope, how much will be left after 3 half-lives?
• Compound interest 4
3600 dollars is placed in an account with an annual interest rate of 9%. How much will be in the account after 25 years, to the nearest cent?
• Doubling
The message is spreading that each day has doubled the number of people who know about it. All know message for 20 days. How long known it eighth people?
• Loan 4
Mr santos borrowed Php.18,000 at 1.5% interest for one year. What was the total amount he paid for the end of the 1-year term?

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