Quandaries and Queries



I was asked a question by a friend of mine’s kid. He asked me if you had a final figure of say 120,000, how do you work out the amount you started with if you added 3% of the starting amount, to the starting amount to get the 120,000.

I put it in a formula as follows 120000 = 3r/100 + r. But I could not work a value for r. I am not sure if that is how you would work it out but can you please help.




Hi Shaun

Your formula is correct.
Since 3/100 = .03, and if you take out the common factor r in your formula you get:

120000 = (1 + .03)r
120000 = (1.03)r


3% of 116504.8544 is 3495.145631
116504.8544 + 3495.145631 = 120000



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