The chart above shows four airlines’ average operating costs per hour for a plane travelling along a certain route. Which expense category contributes most toward B’s total operating costs per hour being higher than A’s ?

So Airline B has a higher total operating cost than Airline A, right? All this question is asking is which category is most responsible for that.

Airline A actually pays more than B for Maintenance and Other, and only a tiny bit less than B for Fuel and Ownership. The category where B is WAY ahead of A is Crew. That’s the category that contributes most to B‘s costs being higher than A‘s.