Half a number plus 5 is 15.What is the number?  Choose the correct choice:
A) 8 B) 20 C) 10 D) 11 E) 12

Rationale: "let x be the number . always replace ` ` is ' ' with an equal sign ( 1 / 2 ) x + 5 = 15 ( 1 / 2 ) x = 15 - 5 ( 1 / 2 ) x = 10 x = 20 correct answer is b"
Answer: B