Answer:
90minutes
Step-by-step explanation:
Let the time taken for passengers to be checked-in be t
Let the number of staff working be w;.
If the time taken for passengers to be checked-in for a flight is inversely proportional to the number of staff working then;
t = kw
when t = 30, w = 5
30 = 5k
k = 30/5
k = 6
to get t when w = 15
t = kw
t = 6(15)
t = 90minutes
Hence it will take 90minutes long
