How long does it take for a deposit of $ 1200 to double at 3​% compounded​ continuously?

Question

Years=

Days=

Answer 1

The previous answer is correct. A quick way to check the result is to use the Rule of 72

( Number of years to double) = 72 / (Interest rate in %)

So 72 / 3% = 24 years.

You can also flip this to find what rate of return you need to get an investment to double

( Interest rate in %) = 72 / ( Number of years needed to double)

Answer 2

A = Pe^rt where A is the current amount, P is the initial amount, r is the interest rate, and t is the time. e is a constant called Euler's number. It has a value of about 2.78128, but it's on most calculators so you can work with it directly (not an approximation.)

2400 = 1200*e^rt

2400/1200 = 2 = e^.03t

log base e or ln is the inverse of e.

ln2 =.03t

ln2/.03 = t = approximately 23.11 years.