Answer: 6*5*5 (choice B)
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Step-by-step explanation:
Each square has a side length of 5 inches, so each square has area 5*5 = 25 square inches. We have 6 such squares to give a total surface area of 6*25 = 150 square inches.
Effectively, this is the same as using the formula below
S = 6x^2
S = 6*5^2
S = 6*5*5
S = 150
x = 5 refers to the side length and S is the surface area. It might help to cut the figure from the paper, and fold it up and you should find that a 3D box will form. There are 6 faces with area of 5*5 each, hence the 6*5*5