Speed = distance / time
speed = 135/3 = 45 miles per hr <==
Answer
Find out the what is the value of x when y = 8 .
To prove
As given
The variables y and x have a proportional relationship.

y = kx
Where k is the constant of proportionality.
As y = 5 when x = 4
Put in the above
5 = 4k

Now find out the value of x , when y = 8


x= 6.5
Therefore when y = 8 than x = 6.4
The answer is -19 because I asked my math teacher and she said-19
Well 2 months and 16 days