When y is divided by 288, the remainder is 45. What is the remainder when the same y is divided by 24?  Choices
A) 20  B) 21  C) 23  D) 25  E) 26

Rationale: "y = 288 * a + 45 = ( 24 * 12 ) * a + 24 + 21 the answer is b ."
Answer: B