Flight Attendant
Just a few minutes before takeoff, a flight attendant notices some interference.
She then asks the passengers:
"Who has their computer on?" Fifteen hands go up.
"Who has their phone on?" Thirteen hands go up.
"Who has both on?" Seven people raise their hands.
"Who has neither a computer nor a phone on?" Nine people respond.
Question:
How many passengers are there on the plane? (Not counting the flight crew)
See
answer
