Donald plans to invest x dollars in a savings account that pays interest at an annual rate of 8% compounded quarterly. Approximately what amount is the minimum that Donald will need to invest to earn over $100 in interest within 6 months? Pick.
A) $1500 B) $1750 C) $2000 D) $2500 E) $3000
Solution:   r = Rate = 8% compounded quarterly.. = 2% per quarter   t = 6 months = 2 quarters   So A = P (1+0.02)^2   =&gt; A = P * 1.0404   Substitute, P for 1500, 1700, 2000.. The A-P should be greater than 100 (since Interest = Amount - principal).   For 2500, interest is 101...   Hence, $2500
<result>D</result>
Donald plans to invest x dollars in a savings account that pays interest at an annual rate of 8% compounded quarterly. Approximately what amount is the minimum that Donald will need to invest to earn over $100 in interest within 6 months?