# Geometric sequence 3

In geometric sequence is a8 = 312500; a11= 39062500; sn=1953124. Calculate the first item a1, quotient q and n - number of members by their sum s_n.

Result

a1 =  4
q =  5
n =  9

#### Solution:

Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

#### To solve this example are needed these knowledge from mathematics:

Do you have a system of equations and looking for calculator system of linear equations?

## Next similar examples:

1. Sequence
Calculate what member of the sequence specified by ? has value 86.
2. Infinity
In a square with side 18 is inscribed circle, in circle is inscribed next square, again circle and so on to infinity. Calculate the sum of area of all these squares.
3. Recursion squares
In the square ABCD is inscribed a square so that its vertices lie at the centers of the sides of the square ABCD.The procedure of inscribing square is repeated this way. Side length of square ABCD is a = 22 cm. Calculate: a) the sum of perimeters of all
4. 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
5. Compound interest
Calculate time when deposit in the bank with interest 2.5% p.a. doubles.
6. Geometric mean
Calculate the geometric mean of numbers a=15.2 and b=25.6. Determine the mean by construction where a and b are the length of the lines.
7. Crystal
Crystal grows every month 1.9 promile of its mass. For how many months to grow a crystal from weight 136 g to 384 g?
8. Wire
One pull of wire is reduced its diameter by 14%. What will be diameter of wire with diameter 19 mm over 10 pulls?
9. Sale
If the product twice price cut by 25%, what percentage was price cut in total?
10. Wood in the forest
The amount of wood in the forest was estimated at 6000 m3. How much wood will be in forest after 2 years if the annual growth of wood is 2.5% each year and logging 30 m3 each year?
11. Geometric progression
Fill 4 numbers between 4 and -12500 to form geometric progression.
12. Machine
Price of the new machine is € 62000. Every year is depreciated 15% of residual value. What will be the value of the machine after 3 years?
13. Deposit
If you deposit 959 euros the beginning of each year, how much money we have at 2.1% (compound) interest after 19 years?
14. 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.
15. JUDr. Usury
Judge JUDr. Usury approved the agreement on guilt and punishment where confessed to pay daily interest 0.18%. How big is a yearly interest? Year has 360 days.
16. 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?
17. Future of libraries
You know that thanks to the Internet, electronic communications and developing online resources on the Internet annually declining number of traditional readership by 17%. These deal is irreversible evolutionary shift from old books from libraries to immed