Question

The successor of “1” is
(a) prime number
(b) co-prime number
(c) composite number
(d) both (a) and (c)

Answer 1

Hint:
Here, we need to find the successor of 1 and answer what kind of number it is. The successor of a number is the number that comes after it. A prime number is a number which is only divisible by 1 and the number itself. A composite number is that number which is not prime. Two integers are coprime if they have only 1 as a common factor.

Complete step by step solution:
We know that the number that comes after 1 is 2. Therefore, we get the successor of 1 as 2.
Now, we need to identify which option is true for the number 2.
A prime number is a number which is only divisible by 1 and the number itself.
We know that the number 2 is only divisible by 1, and 2, that is itself. Therefore, the number 2 is a prime number. So, option (a) is correct.
Two integers are coprime if they have only 1 as a common factor.
We cannot say if 2 is a co-prime number or not unless it is compared with another integer, because co-prime numbers are a pair of numbers.
Hence, option (b) is incorrect.
Next, a composite number is a number which is not prime.
We can see that 2 is not a composite number since 2 is a prime number.
Therefore, option (c) is incorrect.
Finally, a number cannot be both prime and composite.
The number 2 is not a composite number since it is a prime number.

Therefore, option (d) is incorrect.

Note:
Here, it is important to remember the meaning of prime numbers, composite numbers, co-prime numbers, successors and predecessors. We might make a mistake by considering 0 as a successor of 1 instead of the 2. We must that 0 is the predecessor and 2 is the successor of 1. Predecessor is the number that comes before a given number while successor comes after a given number.