Working together, Tim and Tom can type 12 pages in one hour. If they would be able to type 14 pages in one hour if Tom increases his typing speed by 25%, what is the ratio of Tom's normal typing speed to that of Tim?	Choose the correct choice from the following choices:  A) 2 / 1  B) 1 / 2  C) 1 / 3  D) 4 / 1  E) 1 / 4

Rationale: "lets say tim types x pages an hour and tom types y pages an hour . we know that x + y = 12 tom increase speed by 25 % means he will type 1.25 y pages an hour . so we get x + 1.25 y = 14 we need to know the ratio of tom ' s speed to tim ' s speed . this is going to be proportional to the number of pages each can type in an hour , hence ( y / x ) . subtracting both : 0.25 y = 2 so y = 8 . . . so x = 4 ( y / x ) = 8 / 4 = 2 / 1 answer is ( a )"
Answer: A