A contractor is engaged for 30days on the condition that he receives Rs.25 for each dayhe works &is fined Rs.7.50 for each day is absent. He gets Rs.425 in all. For how many dayswas he absent?
Pick one:  A) 5  B) 10  C) 17  D) 25  E) 30

Rationale: "30 * 25 = 750 425 - - - - - - - - - - - 325 25 + 7.50 = 32.5 325 / 32.5 = 10 b"
Answer: B