The cash difference between the selling prices of an book at a profit of 2% and 4% is $3. The ratio of the two selling prices is:
Choose the correct choice from the following options:  A) 55 : 23  B) 52 : 33  C) 51 : 52  D) 45 : 53  E) 51 : 34

Rationale: "let c . p . of the book be $ x . then , required ratio = 102 % of x / 104 % of x = 102 / 104 = 51 / 52 = 51 : 52 c"
Answer: C