We will determine the fuel consumptions of each airline jet and compare them across the number of miled travelled.
It is given that the capacity of a standard airline jet in terms of fuel is as follows:

The standard airline jet burns fuel at a proportional rate with respect to the number of miles ( d ) travelled as follows:

The amount of fuel remaining after travelling ( d ) miles can be expressed as follows:

Plug in the respective quantities and determine the amount of fuel left for the standard airline jet:

Similarly, the capacity of the jumbo airline jet is expressed as follows:

The jumbo airline jet burns fuel at a proportional rate with respect to the number of miles ( d ) travelled as follows:

The amount of fuel remaining after travelling ( d ) miles can be expressed as follows:

Plug in the respective quantities and determine the amount of fuel left for the jumbo airline jet:

Now we will compare the fuel remaining for both models of the jet for the distance ( d ) such that the fuel remaining for each jet is the same as follows:

Now plug in the respective expressions developed in previous steps above:

We have one equation expressed in the form one variable ( d ). We will perform the following algebra:

Hence, the following answers are to be selected:
