alleryTwo cubes of edge b are joined face to face to make a cuboid. What is its total surface area?
A10b2
B12b2
C8b2
D11b2
Answer & Solution
Correct answer: A. 10b2
1. Separate cubes would have 12b2 together.
2. Joining hides two faces, each of area b2.
3. So the cuboid has 12b2 − 2b2 = 10b2.
_Source: NCERT Class 8 Mathematics, Chapter 9 Mensuration, 9.4.2 Cube_
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