160 people surveyed and asked if they believed in UFOs, Ghosts and Bigfoot.

how many people believed in at least one of these things?

42 believed in UFOs 45 believed in ghost
21 believed in Bigfoot 11 believed in UFOs and ghosts
6 believed in ghosts and Bigfoot
4 believed in UFOs and Bigfoot
2 believed in all three

Bigfoot 21-8=13
Ghost 45-15=30
UFOs 42-13=29

72