An aircraft has 116 seats. The airline has found, from long experience, that on average 2.5% of people who have bought tickets for a flight do not arrive for that flight. The airline sells 120 tickets for a particular flight.
(a) Calculate, using a suitable approximation, the probability that more than 116 people arrive for the flight. (ans: 0.647) I have been able to do this part..
(b) Calculate also the probability that there are empty seats on the flight. (ans: 0.185)
I am trying hard to do the 2nd part..but cannot get the ans..plz help..

Question

An aircraft has 116 seats. The airline has found, from long experience, that on average 2.5% of people who have bought tickets for a flight do not arrive for that flight.  The airline sells 120 tickets for a particular flight.
(a)  Calculate, using a suitable approximation, the probability that more than 116 people arrive for the flight. (ans: 0.647)  I have been able to do this part..
(b)  Calculate also the probability that there are empty seats on the flight.  (ans: 0.185)
I am trying hard to do the 2nd part..but cannot get the ans..plz help..