Calculate the ATO time difference directly between WARIC and GRAVE (1826 - 1809 = 17 min), and the total distance between the points is (22+17=39 nm).
Using the CRP-5, Avstar or even the calculator you will find that the result is 138 kt.

Note: in these types of problems, we recommend the following:

• Be very accurate because the choices are very close.
• Calculate the difference between the mentioned points directly and do not use the points between them.
• Use the ATO not the ETO to get the actual calculations.
• Use the normal mathematics to have the decimal results so you can decide the closest number in the choices (in this example: 39 × 60 ÷ 17 you will get a result 137.64, which is definitely closer to 138, the other ways may give you 139 and you will be confused between 138 or 140)