In a group of 150 readers who read science fiction or literacy works or both, 120 read science fiction and 90 read literacy works. How many read both science fiction and literacy works?
Choose one:
A) 70 B) 60 C) 90 D) 100 E) 110

Rationale: consider total number of reader n ( s u l ) = 150 people who read science fiction n ( s ) = 120 people who read literacy works n ( l ) = 90 both science fiction and literacy n ( s â ˆ © l ) = ? n ( s u l ) = n ( s ) + n ( l ) - n ( s â ˆ © l ) 150 = 120 + 90 - n ( s â ˆ © l ) n ( s â ˆ © l ) = 210 - 150 n ( s â ˆ © l ) = 60 so people read both science fiction and literacy works are 160 answer : b
Answer: B