Question

Si n es un número impar, ¿cuál de las siguientes opciones representa un número par? a) 2n +1 b) n (n + 2) c) n + (n-1) e) 2 (n + 1)

Answer 1

Option E) is correct

If n is an odd number then 2(n+1) represents an even number.

Explanation:

Let X=set of all odd numbers

that is
`X={\{1,3,5,7...}\}`

Let Y=set of all even numbers

that is
`Y={\{2,4,6,8...}\}`

Verify that 2(n+1) represents an even number where n is an odd number:

Put n=1 in 2(n+1) we get

2(1+1)=2(2)=4

Put n=3 in 2(n+1) we get

2(3+1)=2(4)=8

Put n=5 in 2(n+1) we get

2(5+1)=2(6)=12

and so on.

From above results we get 2(n+1) represents an even number and is belongs to the set Y when n is an odd number.

Therefore Option E) is correct

If n is an odd number then 2(n+1) represents an even number.