Kemal G. answered • 03/24/17

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Hi Hazel,

This is a compound interest problem. Use the formula

A = P(1+r/n)^nt

r = interest rate in decimals

t = time in years

n = number of times compounded per year

A = future amount

P = initial amount

We are given that our money will triple so we can let A = 3x if we let P = x

r = 0.1

n = 1

then we can write

3x = x(1+(0.1/1))^1t

3x = x (1.1)^t

3 = 1.1^t (divide both sides by x)

take log of each side

log 3 = log 1.1^t

log 3 = t*log(1.1)

t = log 3 / log(1.1)

**t = 11.64 years**

Hazel J.

03/24/17