Question

Thomas invests $50,000 in an account that compounds interest continuously and earns 15%. How long will it take for his money to triple? Round to the nearest tenth of a year.

Answer 1

Answer:

7.3 years

Step-by-step explanation:

Answer 2

Answer:

It will take about 7.3 years for his money to triple.

Step-by-step explanation:

Identify the variables in the formula.

A = 150,000

P = 50,000

r = 0.15

t = ?

A = Pe^rt

Substitute the values into the formula.

150,000 = 50,000e^0.15*t

Solve for t. Divide each side by 50,000.

3 = e^0.15*t

Take the natural log of each side.

ln 3 = ln e^0.15*t

Use the power property and then simplify.  

ln 3 = 0.15*t ln e

ln 3 = 0.15-t

Divide each side by 0.15.

(ln 3) /(0.15) = t

Approximate the answer.

t ≈ 7.3