Percentages + exponential function - examples

  1. Precious metals
    gold_3 In 2006-2009, the value of precious metals changed rapidly. The data in the following table represent the total rate of return (in percentage) for platinum, gold, an silver from 2006 through 2009: Year Platinum Gold Silver 2009 62.7 25.0 56.8 2008 -41.3 4
  2. Crystal
    crystal Crystal grows every month 1.9 promile of its mass. For how many months to grow a crystal from weight 360 g to 593 g?
  3. Demographics
    population The population grew in the city in 10 years from 42000 to 54500. What is the average annual percentage increase of population?
  4. Deposit
    ping_bank If you deposit 959 euros the beginning of each year, how much money we have at 2.1% (compound) interest after 19 years?
  5. Population
    population_1 The town has 65,000 inhabitants. 40 years ago there were 157,000. How many people will live in town in 10 years if the average rate in population is as in previous years?
  6. Computer revolution
    Intel386 When we started playing with computers, the first processor, which I remember was the Intel 8080 from 1974, with the performance of 0.5 MIPS. Calculate how much percent a year rose CPU performance when Intel 486DX from 1992 has 54 MIPS. What
  7. Interest
    MoneyHouse What is the annual interest rate on your account if we put 32790 and after 176 days received 33939.2?
  8. Deposit 3
    interest_money After a year had Martin on bank account € 2028. What was the interest rate when the initial deposit was € 1879?
  9. Car value
    car_old The car loses value 15% every year. Determine a time (in years) when the price will be halved.
  10. The city 2
    kingkong Today lives 167000 citizens in city. How many citizens can we expect in 11 years if their annual increase is 1%?
  11. Compound interest
    bank_3 Compound interest: Clara deposited CZK 100,000 in the bank with an annual interest rate of 1.5%. Both money and interest remain deposited in the bank. How many CZK will be in the bank after 3 years?
  12. The deposit
    money_13 Deposit has been placed for one year at an annual rate of 4.5%. After the added interst amount rose to € 2,612.5. Determine initial deposit.
  13. Combined interest
    bank2 Combined interest: Carol has deposited CZK 100,000 in the bank with an annual interest rate of 1.5%. The money was put into the account 5.5.2016 and withdraw them all before Christmas 20.12.2016. How much money did she withdraw?
  14. Enterprise
    podniky_socik The value of annual production enterprise is 7.1 million USD. The average annual growth rate is 1.5%. What will be value of production at the end of the fifth year?
  15. BTC bubble
    btc_2 One of the world's experts in bubbles -- Prof. Robert Shiller, a Yale economist -- said Bitcoin "was an amazing example of a bubble" back in 2014. If you exchange fiat US dollar $100 to BTC in 2010, now in 2017 have value of 72.9 millions dollars. Find.
  16. Repay, interest, loan
    repay Ramchacha takes a loan amount of 240000 from a bank for constructing a house at the rate of simple interest of 12% per annum. After 1 yr. of taking the loan he rents the house at the rate of 5200 per month. Determine the number of years he would take to re
  17. Radioactive material
    radium A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?
  18. Account operations
    penize_49 My savings of php 90,000 in a bank earns 6% interest in a year. If i will deposit additional php 10,000 at the end of 6 months, how much money will be left if i withdraw php 25,000 after a year?
  19. Investment
    penize_49 1000$ is invested at 10% compound interest. What factor is the capital multiplied by each year? How much will be there after n=12 years?
  20. The crime
    crime The crime rate of a certain city is increasing by exactly 7% each year. If there were 600 crimes in the year 1990 and the crime rate remains constant each year, determine the approximate number of crimes in the year 2025.

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