okay so I don't know how to do this question at all.

it says : John begins to walk faster and accelerates at a rate of 5km/h. How long did it take him to reach a top speed of 12km/h?

A=5
V2=12
t=?
V2=?

But if I use the acceleration equation I have Aav=delta V/delta T
5= v1-12/t


And I don't have enough information to finish it.. but maybe I'm not seeing it.. help please?

His initial velocity was probably 0. That should enable you to finish the question.

use the equation a = v/t where a = acceleration, v = velocity and t = time.
so just plug in your numbers
5 = 12/t

and now just solve for t