Each time you redefine a data series as a contrasting combination chart type, Microsoft Excel displays it behind the series you previously defined.For the same reason, if you combine two chart types that present information similarly but in different orientations - for example, a column and a bar chart - you may be unhappy with your output. If you combine two charts of the same type, your results may be difficult to understand because of the lack of visual differentiation between them.If your chart data includes more than two series, you can create a combination chart that uses three different chart types, one for each series.
