Femi keeps track of a number of gallons of gasoline he uses for each of several trips. Part A: Complete the table. The vehicle consumes gasoline at a constant rate. Part B: How much gasoline could Femi reasonably expect to use on a trip of 110 miles?

The table is attached.

A) The gasoline consume grows as the distance traveled increases. This means that the two quantities are directly proportional.

Therefore, the proportionality constant is given by:
k = gasoline / distance
   = 2 / 40
   = 0.05
We could have used also:
k = 3 / 60
   = 0.05

In order to find the gasoline consumed, you need to multiply the distance by the proportionality constant:
30 × 0.05 = 1.5
55 × 0.05 = 2.75

In order to find the distance traveled, you need to divide the gasoline consumed by the proportionality constant:
3.5 ÷ 0.05 = 70

B) The function of the proportionality found is:
y = 0.05·x
where:
x = distance
y = gasoline

Therefore: 
y = 0.05·110 = 5.5 

Femi for a trip of 110 miles expects to use 5.5 gallons of gasoline.