A number is doubled and 5 is added. If the resultant is trebled, it becomes 135. What is that number? Choose the correct answer
A) 12 B) 29 C) 20 D) 15 E) 99

Rationale: "explanation : let the number be x . therefore , 3 ( 2 x + 5 ) = 135 6 x + 15 = 135 6 x = 120 x = 20 answer : c"
Answer: C