Answer:
Explanation:
Yellow block closest side and farthest side: 2x1=2 2x2=4
Yellow block right and left side: 1x1=1 1x2=2
Yellow block bottom: 2x1=2
Yellow block top: 2x1=2
Purple block closest side and farthest side: 5x2=10 10x2=20
Purple block right and left side: 2x3=6 6x2=12
Purple block bottom: 5x3=15
Purple block top: 5x3=15 15-2=13
2+2+2+1+1+13+10+10+6+6+15= 68
The overlap effects the calculation of the surface area because the bottom of the yellow block and a part of the purple block overlaps making it so that you would count it two times instead of the area that is visible.
I like to think of it as spray painting the blocks and seeing where the paint sprays.