If a student loses 6 kilograms, he will weigh twice as much as his sister. Together they now weigh 126 kilograms. What is the student's present weight in kilograms? Pick one.
A) 82
B) 84
C) 86
D) 88
E) 90

Rationale: "let x be the weight of the sister . then the student ' s weight is 2 x + 6 . x + ( 2 x + 6 ) = 126 3 x = 120 x = 40 kg then the student ' s weight is 86 kg . the answer is c ."
Answer: C