An investment E gained an interest payment of $250 each month when the annual interest rate was 8%, how much more should we invest annually if we want to gain 12% more per month with a new annual interest rate of 7.5% ?  Choose the correct choice from the following choices:
A) $9,360 B) $9,100 C) $8,250 D) $7,300 E) $7,150
Answer is D : 7,300   An investment E gained an interest payment of $250 each month when the annual interest rate was 8%,Interest per annum with 8% interest rate is = 250* 12 = Principal * Interest Rate(8/100)   This gives Principal as 37,500$   For an revised interest of 12% more and new interest rate of 7.5% , ie. 250* 12 * 1.12 = Principal * Interest Rate (7.5/100)   This gives the new Principal as 44,800.   The question is how much more should we invest, so 44,800 - 37,500 = 7,300.$7,300
<result>D</result>
An investment E gained an interest payment of $250 each month when the annual interest rate was 8%, how much more should we invest annually if we want to gain 12% more per month with a new annual interest rate of 7.5% ?