Multiple choice

The positive difference between the cubes of any two positive integers can't be

  1. a multiple of 3

  2. a prime number

  3. an even integer

  4. an odd integer

  5. the cube of an integer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let us try two pairs of consecutive positive integers starting with an odd number and an even number, say (1, 2) and (2, 3). The differences between the cubes of the two numbers are (8 - 1) = 7 in  the first case, and (27 - 8) = 15 in the second case. Among the choices, it is only (2) which is true in both these cases.

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