Question

Which of these numbers is not an integer: $-31,74,22.5,-7,\text{or}\text{19?}$

Short answer

The number22.5 is not an integer.

Step-by-step solution

Step-1 – Concept of integers

Integers include the positive and negative whole numbers including zero. An integer cannot be a decimal or fractional part with it.

The set of integers is denoted by the numbers $...,-4,-3,-2,-1,0,1,2,3,4,...$

Step-2 – Identify the integers

In the given numbers, observe that the only number with decimal part is 22.5. Rest all the numbers are whole numbers with positive or negative sign.

So, the whole numbers with positive or negative sign are integers.

Step-3 – Identify the non-integer

Since 22.5 is the only number that is not a whole number as it contains the fractional part, so this is not an integer.

Thus, the number that is not integer is 22.5.