# 8th grade (13y) + geometric progression - examples

1. Profitable bank deposit 2012
Calculate the value of what money lose creditor with a deposit € 9500 for 4 years if the entire duration are interest 2.6% p.a. and tax on interest is 19% and annual inflation is 3.7% (Calculate what you will lose if you leave money lying idle at negative
2. Wire
One pull of wire is reduced its diameter by 14%. What will be diameter of wire with diameter 19 mm over 10 pulls?
3. Sale
If the product twice price cut by 25%, what percentage was price cut in total?
4. Wood in the forest
The amount of wood in the forest was estimated at 7000 m3. How much wood will be in forest after 2 years if the annual growth of wood is 2.2% each year and logging 70 m3 each year?
5. Series
Andrew wrote this series of numbers: 1,3,7,15, .... n. Which number in the series does not belong? ?
6. 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.
7. Number
Is number 5.146852 irrational?
8. Miraculous tree
Miraculous tree grows so fast that the first day increases its height by half the total height of the second day by the third, the third day by a quarter, etc. How many times will increase its height after 6 days?
9. Eight palm
There grows 8 palms by the sea. At the first sitting one parrot, on second two, on third sits four parrots on each other twice the previous parrots sitting on a previous palm. How many parrots sitting on eighth palm?
10. Probably member
Look at the series 2,6,25,96,285, ? What number should come next?
11. Progression
12, 60, -300,1500 need next 2 numbers of pattern
12. Tickets
On Monday, 33 tickets were sold. Every next day, twice as many as the previous day. How many tickets were sold on Friday and how many totally from Monday to Friday?

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