How many numbers from 10 to 50 are exactly divisible by 3 Pick one:
A) 11  B) 13  C) 15  D) 18  E) 19

Rationale: "12 , 15 , 18 , 21 , 24 , 27 , 30 , 33 , 36 , 39 , 42 , 45,48 . 13 numbers . 10 / 3 = 3 and 50 / 3 = 16 = = > 16 - 3 = 13 . therefore 13 digits b )"
Answer: B