Comparing speed and acceleration from motion diagrams

[samxel]

Homework Statement

If i have a picture of a motion diagram of 2 objects , how do i tell when they have the same speed and acceleration?
and at what time one object is ahead of Object B ?

I have a diagram here
http://i33.tinypic.com/28kpk02.jpg

Homework Equations

none

The Attempt at a Solution

Since they are both moving in the same direction I see the B is moving in constant speed
(same amount of displacement in each equal intervals of time)
So they may have the same speed at t=1 and t=4 OR they may have the same speed in between t=1 and t=4 ? Just can't figure Which.

 

[kuruman]

Try again. At t=1 and t=4 they have the same position not the same velocity. Look for equal displacements (differences in position) over the same time interval.