In a group of 650 readers who read science fiction or literacy works or both, 250 read science fiction and 550 read literacy works. How many read both science fiction and literacy works?	Select the correct option.
A) 650  B) 250  C) 150  D) 100  E) 400

Rationale: "consider total number of reader n ( s u l ) = 650 people who read science fiction n ( s ) = 250 people who read literacy works n ( l ) = 550 both science fiction and literacy n ( s â ˆ © l ) = ? n ( s u l ) = n ( s ) + n ( l ) - n ( s â ˆ © l ) 650 = 250 + 550 - n ( s â ˆ © l ) n ( s â ˆ © l ) = 800 - 650 n ( s â ˆ © l ) = 150 so people read both science fiction and literacy works are 150 answer : c"
Answer: C