SOLUTION: how many years would it take at 10% per year for $1360 to double?

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Question 960412: how many years would it take at 10% per year for $1360 to double?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+2%2A1360+=+2720+
Let +n+ = the number of years it
takes for $1360 to double
-------------------------
+2720+=+1360%2A%28+1+%2B+.1+%29%5En+
+2720+=+1360%2A%281.1%29%5En+
Take the log of both sides
+log%28+2720+%29+=+log%28+1360+%29+%2B+log%28+%281.1%29%5En+%29+
+log%28+2720+%29+=+log%28+1360+%29+%2B+n%2Alog%28%28+1.1+%29%29+
+3.4346+=+3.1335+%2B+n%2A.04139+
+n%2A.04139+=+.3011
+n+=+.3011+%2F+.04139+
+n+=+7.2747+
It would take about 7 years and 4 months
check:
+2720+=+1360%2A%28+1+%2B+.1+%29%5En+
+2720+=+1360%2A%28+1+%2B+.1+%29%5E7.2747+
+2720+=+1360%2A2.0004+
+2720+=+2720.544+
error due to rounding off
close enough to get the year and month