SOLUTION: Find the sum of the first 10 terms of the series defined by the formula: an = -2n + 5 a. 3 b. 2 c.-60 d. -15 A 5 inch spike is being pounded in to

Algebra ->  Sequences-and-series -> SOLUTION: Find the sum of the first 10 terms of the series defined by the formula: an = -2n + 5 a. 3 b. 2 c.-60 d. -15 A 5 inch spike is being pounded in to       Log On


   



Question 82644: Find the sum of the first 10 terms of the series defined by the formula:
an = -2n + 5
a. 3
b. 2
c.-60
d. -15

A 5 inch spike is being pounded in to a log. Every time you hit the hammer 1/4 of the remaining spike goes into the log. What kind of sequence or series is definied by the total distance the spike goes into the log?
a. arithmetic sequence
b. arithmetic series
c. geometric sequence
d.geometric series


Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the sum of the first 10 terms of the series defined by the formula:
a(n) = -2n + 5
-7,-9,-11,.....,-25
S(10) = 10/2(-7+-25)
S(10) = 5(-32)
s(10) = -160
a. 3
b. 2
c.-60
d. -15
Comment: Check your problem again.
==========================================
A 5 inch spike is being pounded in to a log. Every time you hit the hammer 1/4 of the remaining spike goes into the log. What kind of sequence or series is definied by the total distance the spike goes into the log?
5, 5(1/4), 5(1/5)^2, 5(1/4)^3,....
Total distance in = 5^(1/4)^n where n=# of hammer strikes.
Geometric with a(1)=5 and r=(1/4)
===============
a. arithmetic sequence
b. arithmetic series
c. geometric sequence
d.geometric series
===================
Cheers,
Stan H.