A sum of $500 amounts to 600 in 2 years at simple interest. If the interest rate is increased by 10% it would amount to how much ?  Choices:
A) $ 500  B) $ 700  C) $ 800  D) $ 600  E) $ 300

Rationale: s . i = 600 - 500 = 100 p = $ 500 t = 2 years r = 100 * 100 / 500 * 2 = 10 % new rate = 10 + 10 = 20 % new s . i . = 500 * 20 * 2 / 100 = $ 200 new amount = 500 + 200 = $ 700 answer is b
Answer: B