In a group of 400 readers who read science fiction or literacy works or both, 250 read science ...
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?
Answer/Solution
80
Steps/Work
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:B
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:B