Question

The whole number which does not have a predecessor in the whole number system?
(a) 0
(b) 1
(c) 2
(d) None of the above

Answer 1

Hint: In the above problem, we are asked to find the whole number which has no predecessor in the whole number system. We know that, in the whole number system the first number starts from 0 then 1 then 2 then 3 and so on. So, basically any number which lies before 0 is not in the whole number system because the highest number in the whole number system is infinite so the number which does not lie in the whole number system is the number which lies before 0.

Complete step by step answer:
First of all, we are going to write the entities which lie in the whole number system.
0, 1, 2, 3, 4…….
Now, we are asked to find the predecessor among the whole numbers which do not lie in this whole number system. So, the numbers which do not lie in this whole number system are the number either before 0 or the number that lies after the highest number in the above whole number system. Now, the highest number in the above whole number system is infinite so we are not considering the number after infinite.
So, we are considering the number before 0.
We know that the predecessor of any number is one less than that number. So, the predecessor of 0 is 1 less than 0 which is equal to the subtraction of 1 from 0 which will give us:
$0-1=-1$
Now, we know that -1 is not the number that lies in the whole number system so 0 is the number in the whole number system whose predecessor does not lie in the whole number system.

So, the correct answer is “Option a”.

Note: To solve the above problem, you need to have knowledge of what whole numbers are and how the number line is represented. Without these core concepts you cannot solve this problem. After that, you should know what the predecessors are. So, make sure you have a good understanding of these concepts.