Nanette must pass through three doors as she walks from her company's foyer to her office. Each of these doors may be locked or unlocked. Let C be the event that at least two doors are in the same condition. List the outcomes of C.
[Let "L" designate "locked" and "U" designate "unlocked".]
A) {LLL, UUU, LLU, LUL, ULL}
B) {LLU, LUL, ULL, LUU, ULU, UUL}
C) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU}
D) None of these.

Question

Quizplus · Accepted Answer

To satisfy the condition of C, either two doors must be locked or two doors must be unlocked. Therefore, the outcomes of C include:
- LLL (all locked)
- UUU (all unlocked)
- LLU (first two locked, last unlocked)
- LUL (first and last locked, middle unlocked)
- ULL (last two locked, first unlocked)
- LUU (first two unlocked, last locked)
- ULU (second locked, others unlocked)
- UUL (last two unlocked, first locked)

All of these outcomes meet the condition of C, so the best choice is C.

Nanette Must Pass Through Three Doors as She Walks from Her