Question

Which of the following pairs (x,y) of whole numbers, when subtracted(i.e. x - y) does not give a whole number?

• A.
  5, 2
• B.
  7, 10
• C.
  3, 1
• D.
  0, 1

Answer 1

Answer: (B), (D)

The correct options are
B
7, 10
D

0, 1
Whole numbers are not closed under subtraction. So , subtraction of two whole numbers might not result in a whole number.

Whole numbers are {0,1,2,3,...}

I. 5 - 2 = 3, a whole number.
II. 7 - 10 = -3, not a whole number.
III. 3 - 1 = 2, a whole number.
IV. 0 - 1 = -1, not a whole number.