Physics Acceleration Science question

I need help with a question in my science class. It'll to do with acceleration.
Block A is traveling at an acceleration of 12.5cm/s^2
Block B is traveling at an acceleration of 3.5cm/s^2
They are 130 cm apart.

How long will it take for block A to reach block B?

(I'd like for the formula, and explained. The answer is not really needed.)

You didn't mentioned the directions of the blocks.
Are they moving along the same direction or towards each other ?
Also, did they started from rest or had some initial velocities ?

Well, considering the first case (moving in same direction) and starting from rest ;

To find the time "t" in which block 'A' will reach/overtake block 'B',
We can equate the distances of the two blocks in following way,

Distance travelled by Block 'A' = 130 cm + Dist. travelled by Block 'B'

0.5 x 12.5 x (t)^2 = 130 + 0.5 x 3.5 x (t)^2

OR

0.5 x (t)^2 x (12.5 - 3.5) = 130

OR

(t)^2 = 130 / 4.5 = 28.88

OR

t = 5.37 sec.