A number is doubled and 9 is added. If the resultant is trebled, it becomes 57. What is that number?	Choose the correct choice from the following options:
A) 5
B) 6
C) 8
D) 7
E) 4

Rationale: "let the number be x . then , 3 ( 2 x + 9 ) = 57 2 x = 10 = > x = 5 answer : a"
Answer: A