# Percentages + exponential function - examples

1. Profit growth The profit of a company increased by 25% during the year 1992, increased by 40% during the year 1993, decreased by 20% in the year 1994 and increased by 10% during the year 1995. Find the average growth in the profit level over the four years periods?
2. 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 The population grew in the city in 10 years from 42000 to 54500. What is the average annual percentage increase of population?
4. Deposit 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 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 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 What is the annual interest rate on your account if we put 32790 and after 176 days received 33939.2?
8. Deposit 3 After a year had Martin on bank account € 2028. What was the interest rate when the initial deposit was € 1879?
9. Car value The car loses value 15% every year. Determine a time (in years) when the price will be halved.
10. The city 2 Today lives 167000 citizens in city. How many citizens can we expect in 11 years if their annual increase is 1%?
11. Compound interest 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 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 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. The city At the end of 2010 the city had 248000 residents. The population increased by 2.5% each year. What is the population at the end of 2013?
15. Enterprise 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?
16. BTC bubble 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.
17. Repay, interest, loan 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
18. Precious metals 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
19. Radioactive material A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?
20. Account operations 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?

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