# Power + exponential function - problems

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. Subsets How many are all subsets of set ??
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. Loan Apply for a \$ 59000 loan, the loan repayment period is 8 years, the interest rate 7%. How much should I pay for every month (or every year if paid yearly). Example is for practise geometric progression and/or periodic payment for an annuity.
6. Interest Calculate how much you earn for 10 years 43000 deposit if the interest rate is 1.3% and the interest period is a quarter.
7. To the cinema Jane at 8 am got message that all 1093 school pupils will go to the cinema. Within 20 min she said it to the three friends. Each of them again for 20 minutes said to the other three. In this way the message spread further. At what time all the children in.
8. The city 2 Today lives 167000 citizens in city. How many citizens can we expect in 11 years if their annual increase is 1%?
9. 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?
10. Exponential equation Solve for x: (4^x):0,5=2/64.
11. 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?
12. Exponential equation Find x, if 625 ^ x = 5 The equation is exponential because the unknown is in the exponential power of 625
13. Geometric progression In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is: sn≤217.
14. 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
15. Radioactive material A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?
16. Investment 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?

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