Let
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are

where
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if
, and we know that this happens after two hours, i.e. at 

Solving this equation for v we have

So, train A is travelling at 105 km/h. This implies that train B travels at

To find average, add up the values given and then divide that number by the amount of values that you added to make the larger number.
For example:
If he ran -8 yards first and -6 yards second and they are asking you to find the average, add -8 and -6. You get -14. If you then divide by 2 because you added 2 numbers together, you end up with -7.
Hope this helps!
Answer:
3
Step-by-step explanation:
Three times three equals nine. Or you can just go by one times one, two times two, three times three.