To see many other similar (and different) solved problems on simple interest accounts, look into the lesson
- Simple interest percentage problems
in this site.
Work Shown:
A = P*(1+r*t)
A = 700*(1+0.18*14/12)
A = 847
This is a slightly longer approach:
i = P*r*t
i = 700*0.18*14/12
i = 147 dollars is the interest only
A = P+i
A = 700+147
A = 847 total due (principal + interest)
Pay careful attention to the fact that I used t = 14/12, and not t = 14, since t represents the time in years.
14 months = 14/12 years = 1.1667 years approximately.