CUET Preparation Today
If $σ(n)$ = Sum of all positive divisors of n, n ∈ N, then what is the value of $σ(30)$ ? |
68 72 76 78 |
72 |
The correct answer is option (2) : 72 $σ(30)$ +ve divisions of 30 are $1, 2, 3, 5, 6, 10, 15, 30$ $∴σ(30)=1+2+3+5+6+10+15+30$ $=72$ |
