12 31/100 is the mixed fraction because in a decimal all the numbers to the left are whole numbers and all the numbers to the right are numbers that are part of a whole. Just like in a mixed fraction there is a whole number and a fraction in a mixed number. Since 12 is in the left it is the whole number and since 31 is to the right and in the place value 31 is ending in the hundredths place so that's why the fraction is, 31/100. That's how you came to know that 12 31/100 is the fraction for 12.31.
hey mate..
the position at which the tips of the scissors will be FARTHER APART is at position B.
as the angle made by the scissors at the centre is greater in position B.
Whole numbers are a subset of integers, which in turn are a subset of rational numbers.
So, every whole number is an integer, and every integer is a rational number.
So, it is possible for a rational number not to be an integer. Think of any decimal number: 1.356 is a rational number, but it's not an integer.
On the other hand, if a number is not an integer, it can't be a whole number, because all whole numbers are integers.