If the satellite moves at a speed of 27,000 km p/h, your answer depends on the question.
This could be written in an algebraic expression, such as:
27,000x = S [for S stands for the ultimate speed of the satellite]
Of course, if this is a 3rd grade level question, I highly doubt they have even gotten started to including the alphabet into math.
So, I would suggest plugging 4 into X. To explain this to her, just say that the speed needs to be multiplied by the amount of hours it has traveled. (I got 4 because there is a '4' in the question instead of 'for').
Meaning, 27,000 x 4 = 108,000 km per 4 hours
If her teacher decides to ask why that number, have her explain the question did not make sense so she plugged in a 4 to find an answer to a certain amount of hours.
D because there are 10 gallons of gas remaining as you can see on the y axis and 10 gallons is being used for each 10 miles because 10 x 10 is 100 and the graph is counting up by 10
