In a class of students, 1/2 of the number of girls is equal to 1/5 of the total number of students. What is the ratio of boys to girls in the class?  Select the correct option.
A) 1 / 2  B) 3 / 2  C) 1 / 3  D) 2 / 3  E) 4 / 3

Rationale: "( 1 / 2 ) g = ( 1 / 5 ) ( b + g ) 5 g = 2 b + 2 g 3 g = 2 b b / g = 3 / 2 . the answer is b ."
Answer: B