2. Questions Bank
  3. 7th Class
  4. Mathematics
  5. Related to Competitive Exam

7th Class Mathematics Related to Competitive Exam Question Bank Cube and Dice

  • question_answer
    From \[10\times 10\times 10\] cube, which is formed by combinations of \[1\times 1\times 1\] cubes, a layer of the smaller cubes is removed. What will be the number of \[1\times 1\times 1\] cubes present in this new cube?

    A) 900                             

    B) 488

    C) 512     

    D) 729

    Correct Answer: C

    Solution :

        A \[10\times 10\times 10\] cube has 10 cubes of \[1\times 1\times 1\]cubes along its length, breadth and width each. If we remove a layer of \[1\times 1\times 1\] cubes (the smaller cubes) then the new cube will have following dimensions: Length\[=10-1-1=8;\]breadth\[=10-1-1=8\] and width\[=10-1-1=8.\] So the number of \[1\times 1\times 1\] cubes in this \[8\times 8\times 8\] cube \[=8\times 8\times 8=512.\]                           


You need to login to perform this action.
You will be redirected in 3 sec spinner