SOLUTION: A sum of money doubles itself in 10 years. The number of years it would triple itself is?

Question 1209369: A sum of money doubles itself in 10 years. The number of years it would triple itself is?
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

Let a be the initial amount; let r be the growth factor each year. Then, since the amount doubles in 10 years,

= 1.07177 to several decimal places.

We want to find the number of years n it takes the amount to triple:

The variable is in an exponent, so use logarithms.

= 15.85 to two decimal places

ANSWER: approximately 15.85 years

Of course, if we want an answer in whole numbers of years we need to round that up to 16 years.

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