Can someone help me please :C
Shelly, Jess, and Andrea are all working at an amusement park for the summer. The manager finds out that one of them left the key in the door to the security office. When he asked them who did it, they replied:

Shelly: Jess did it.
Jess: I didn’t do it.
Andrea: Jess did not do it.

The manager believed Jess. Use an indirect proof to show that Jess did not leave the key in the security office door.

Hint: Begin by assuming Jess did leave the key in the door.

Question

Can someone help me please :C
Shelly, Jess, and Andrea are all working at an amusement park for the summer. The manager finds out that one of them left the key in the door to the security office. When he asked them who did it, they replied:
 
Shelly: Jess did it.
Jess: I didn’t do it.
Andrea:  Jess did not do it.
 
The manager believed Jess. Use an indirect proof to show that Jess did not leave the key in the security office door.
 
Hint: Begin by assuming Jess did leave the key in the door.

lgbasallote · Answer

i have seen this question so many times, and I just have to wonder; what topic does this come from?

anonymous · Answer

Assuming Jess did leave the key in the door, that would mean Shelly was right. Assuming that Jess did leave the key in the door, Jess was wrong. Assuming Jess did leave the key in the door, Andrea was wrong. Since two of the three statements contradict the assumption, the original is correct, Jess did not leave the key in the door.

anonymous · Answer

is this flvs?

anonymous · Answer

Yup flvs geometry :C

anonymous · Answer

I mean it's the opposite Since two out of three statements are false, we can conclude that the opposite is true, Jess did leave the key in the door.

anonymous · Answer

Look here http://openstudy.com/study#/updates/500d743be4b0ed432e0fdbde

anonymous · Answer

:C im sorry im still a little confused

anonymous · Answer

wait nevermind i think i kinda got it thanks!