1.Represent the rows with trains and the columns with stations.
2.Bring the train to the stations.A train should pass all the stations.The passengers in a train should be add together.
3.Remember a train can move to all stations but a stations cant move to a train .
4.If there is another train(row) bring to all the stations just like the first train.
This technique is applicable for multiplication of matrices .If you have any other problem with matrices or unable to understand the technique above,do comment.