Question

A relation $f$ on the set $N$ of natural numbers is defined by $f=(n,n+3):nϵN$. The range of $f=N-$.{...}

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (A), (B), (C)

1
2
3

The set of natural numbers include all the positive integers except 0.

Therefore

$Nϵ[1,2,\mathrm{3...}\infty )$

Hence

$f\left(n\right)=n+3$ implies

$f\left(n\right)ϵ\left[\right(1+3),(2+3)...\infty )$

$\Rightarrow f\left(n\right)ϵ[4,\mathrm{5..}\infty )$

Thus
$f\left(n\right)ϵN-\{1,2,3\}$.