A. The green face of the figure is 6 square units. It is congruent with the contrary face which is obscured from view.
The back face, also non viewed, is 6 square units.
Blue faces total also is 6 square units, and the yellow also 6 square units.
Then, the surface area of this figure is:
(6x2)+6+6+6=30 square units.
B. So, if the top two cubes are removed, then the green face and its contrary would be 5 square units each.
The back face would be 4 square units, the blue faces still being 6 square units.
And the yellow faces would be 4 square units.
So, the surface area of the new figure would be:
(5x2)+4+6+4=24 square units.
