How long does it take to triple an investment of 5000 in an

How long does it take to triple an investment of $5000 in an account that earns 6.85% annual interest compounded continuously?

10 years

16 years

5 years

12 years

Solution

Investment = $5000

Rate = 6.85%

= 0.0685

Amount = $15000 (bcoz of triple investment)

so

V_t =P₀ (1+ r)^t

^{15000 = 5000(1.0685)^t}

₃ =(1.0685)^t

^{Taking ln both side we get}

^{ln(3) = t*ln(1.0685)}

^{t = 16.58 years required to triple an investment .}

^Answer