Answer
180279
Work Step by Step
The sum of first n natural numbers is given by,
$\frac{n\times(n+1)}{2}$
7 + 8 + 9 + 10 + ··· + 600
= (1+2+3+ ... +600) - (1+2+3+ ... +6)
= $\frac{600\times601}{2}$ - $\frac{6\times7}{2}$
= 180300 - 21
= 180279