At the pie eating contest, max ate 2⁄5 of a pie and jen ate 6⁄8 of a pie. how many pies did they eat all together?

I think you have to find a common multiple for the denominators 5 and 8 which would be 40. so it would be 6/40 and 2/40. then I think, you  would add or multiple, depending on the situation, 6 and 2