My dumb brain can’t think anymore helppp

First you need to add each and everyone of the seats in the plane so
14 + 64 + 108 = 186

Then divide 186 by 2 to determine the half
And that is 93

Then multiply each by the seats so
5/7 * 14 = 10
5/16 * 64 = 20
5/9 * 108 = 60

Then you add everything and it’s equals to 90 and since it’s below 93 half of the seats aren’t being used

Hope this helps!