In a sports club with 30 members, 17 play badminton and 21 play tennis and 2 do not play either. How many members play both badminton and tennis?
Choose the correct choice from the following answers
A) 7	B) 8	C) 9	D) 10	E) 11

Rationale: "let x play both badminton and tennis so 17 - x play only badminton and 19 - x play only tennis . 2 play none and there are total 30 students . hence , ( 17 - x ) + ( 21 - x ) + x + 2 = 30 40 - 2 x + x = 30 40 - x = 30 x = 10 so 10 members play both badminton and tennis . d"
Answer: D