A invested $100 in a business after 6months B invested $200 in the business. End of the year if they got $100 as profit. Find A shares? Choose the correct choice from the following answers.
A) $ 100
B) $ 75
C) $ 20
D) $ 120
E) $ 50

Rationale: "a : b = 100 * 12 : 200 * 6 a : b = 1 : 1 a ' s share = 100 / 2 = $ 50 answer is e"
Answer: E