SOLUTION: how long it will take for a sum of money to double itself at 10% simple intrest?

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Question 927754: how long it will take for a sum of money to double itself at 10% simple intrest?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
How long does it take for a sum of money to double itself at a simple interest rate of 10% per annum?

You presumably know the equation for simple interest calculations :

I+=%28P+%2A+%28R%2F100%29+%2A+T%29

If you want the sum to double, then the interest must equal the principal (P), the amount you started with.
Therefore I+=+P, hence
I+=%28P+%2A+R+%2A+T%29, from which
P+=%28P+%2A+10+%2A+T%29%2F100
100P+=+P+%2810%29+T
.
T+=100+P%2F+10P=10+years.

example:
I+=P+%2A+R+%2A+T
let
+P be $60.00
r+ be 10% per year, or in decimal form, 10%2F100=0.1
+t is 10 years time period

To find the simple interest, we multiply I+=P+%2A+R+%2A+T=60%2A0.1%2A10=60
so, the interest is: $60.00 which is equal to the principal amount, and it means our principal amount is doubled