Given:
Principal value = $640
Rate of interest = 3.9% not compounded
Number of years = 8
To find:
The amount after 8 years.
Solution:
It is given that the interest is not compounded. It means, we need to find simple interest.
Formula for simple interest:
where, P is principal, r is rate of interest and t is time in years.
Put P=640, r=0.039 and t=8.
So, the interest is $199.68.
Now, amount after 8 years is
where, P is principal and I is interest.
Therefore, the amount after 8 years is $839.68.