The slope is defined as the difference in the y-values of two points on the line divided by the difference of the corresponding x-values. Thus, our slope is:
It's simple. So the only cards which are divisible by 2 or 3 are: 2,3,4,6,8,9,10,12,14,15,16,18,20,21,22,24. The formula of probability is P= m/n. Where m-Number of ways it can happen and n- Total number of outcomes.