Problema Solution
Use logarithms to solve the problem.
Find the interest rate needed for an investment of $3900 to double in 5 yr if interest is compounded continuously. (Round your answer to two decimal places.)
Answer provided by our tutors
A=Pe^rt.
7800=3900*e^5r.
2=e^5r.
ln(2)= 5r ln(e).
0.693=5r.
r=0.693/5
=0.1386.
rate of interest =13.86%.