The cash difference between the selling prices of an book at a profit of 5% and 10% is $3. The ratio of the two selling prices is:
Answers:  A) 21 : 22  B) 52 : 33  C) 52 : 53  D) 45 : 53  E) 51 : 34

Rationale: "let c . p . of the book be $ x . then , required ratio = 105 % of x / 110 % of x = 105 / 110 = 21 / 22 = 21 : 22 a"
Answer: A