In a group of 400 readers who read science fiction or literacy works or both, 250 read science fiction and 230 read literacy works. How many read both science fiction and literacy works?	Choose the most appropriate option.
A) 70  B) 80  C) 90  D) 100  E) 110
Consider total number of reader n(S U L) = 400   People who read science fiction n(S) = 250   People who read literacy works n(L) = 230   both science fiction and literacy n(S ∩ L) = ?   n(S U L) = n(S)+ n(L) - n(S ∩ L)   400 = 250 + 230 - n(S ∩ L)   n(S ∩ L) = 480 - 400   n(S ∩ L) = 80   SO People read both science fiction and literacy works are 80   ANSWER:80
<result>B</result>
In a group of 400 readers who read science fiction or literacy works or both, 250 read science fiction and 230 read literacy works. How many read both science fiction and literacy works?