That is a somewhat reasonable answer. The reason that I don't consider it exactly correct is that the original claim was: "Uber passengers were paying only 41%

That is a somewhat reasonable answer. The reason that I don't consider it exactly correct is that the original claim was: "Uber passengers were paying only 41% of the actual cost of their trips." What you have calculated is that Uber passengers paid 78.8% of the cost of operating the company in 1H2015. The cost of operating the company isn't the same thing as the cost of all their trips. The company does a lot more than provide trips.