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a large rectangular prism measuring 3 cm by 5 cm by 6 cm is painted and then divided up
into small cubes measuring 1 cm to a side
what is the total unpainted surface area of the small 1 cm^3 cubes?
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The surface area of the large prism is 2*(3*5 + 3*6 + 5*6) = 126 cm^2.
So, the painted area is 126 cm^2.
The number of small cubes is 3*5*6 = 90.
Their total surface area is 90 times 6 cm^2, i.e. 6*90 = 540 cm^2 (since each small cube has 6 faces).
THEREFORE, unpainted area is 540 - 126 = 414 cm^2. ANSWER
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