Question

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?
a.80
b.160
c.220
d.400

Answer 1

say x = read both science fiction and literacy works
250 = read either science fiction
230 = read literacy works

400 = 250 + 230 - x
solve for x = (250 + 230) - 400
gives; x = 80 read both science fiction and literacy