[tex]d = 2 \times (1 + 2 + 3 + ... + 124) + 125[/tex]
[tex]d = 2 \times \frac{124(124 + 1)}{2} + 125[/tex]
[tex]d = 124(124 + 1) + 125[/tex]
[tex]d = 124 \times 125 + 125[/tex]
[tex]d = 125(124 + 1)[/tex]
[tex]d = 125 \times 125[/tex]
[tex]d =5\times 5\times 5\times 5 \times 5 \times 5 [/tex]
[tex]d=25 \times 25 \times 25={25}^{3}=>c.p [/tex]
