You would first draw the bar graph and on the y axis, which goes up and down, you would list the numbers 20-40(to make it faster and easier) and on the x axis, left and right, the colors which are red, blue and green. Then just draw a bar from the x axis on each section up the the number of the markers. For example, “red” would be on the x axis so you would draw a bar up to 25. lmk if you want a picture since i’m not good with explaining things lol