For any number Z, Z* is defined as the greatest positive even integer less than or equal to y. What is the value of 6.15 – 6.15*?
Choose the correct choice from the following answers:
A) 1.5  B) 0.15  C) 6.25  D) 0.25  E) 6.0

Rationale: "since z * is defined as the greatest positive even integer less than or equal to z , then 6.15 * = 6 ( the greatest positive even integer less than or equal to 6.15 is 6 ) . hence , 6.15 – 6.15 * = 6.15 - 6 = 0.15 answer : b ."
Answer: B