A number is doubled and 9 is added. If the resultant is trebled, it becomes 63. What is that number?  Choose the correct choice from the following answers
A) 3.5	B) 6	C) 8	D) 7	E) 4

Rationale: "let the number be x . then , 3 ( 2 x + 9 ) = 63 2 x = 12 = > x = 6 answer : b"
Answer: B