D: Please help me, I'm so bloody confused!

Question

anonymous · Answer

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.

amistre64 · Answer

like i tell my daughter;  .... dont bring over any drama :)

amistre64 · Answer

shelly seems to have a guilty conscience and wants to ensure that someone else gets blamed; id keep my eye on her ....

turingtest · Answer

assuming Jess left the key in the door, let's call that statement (J), and Jess not leaving the key in the door we call (~J)

turingtest · Answer

if J, then Andrea and Jess are lying and Shelly is telling the truth

A : ~J
J : ~J
S : J

if ~J then Shelly is lying, and the others are telling the truth

...still trying to draw a conclusion from this...

amistre64 · Answer

shelley did it ... im sure of it :)

anonymous · Answer

thanks ((: