The step function is characteristic of the floor or ceiling functions, which map a real number to an integer. There's clearly a factor of 2, indicated by two units of y for every one unit of x.
The open and filled circles indicate, for example, f(1)=2, f(1.01)=4. That means we're rounding up, so we're using the ceiling function.

Answer: second choice
The answer to this problem would be 2.5.
Hello,
Answer A
d :the distance in miles
t: the time in hours
v: the speed in miles/hours (vistesse)
d=v*t
==>d=40*4=160(mi)
d=55*x=160==>x=160/55=2.909090... (mi/(mi/h)=h)≈2.91(hours)