Question 321484
Hint: Recall that *[Tex \LARGE 1+2+3+...+n=\sum_{i=1}^{n} i = \frac{n(n+1)}{2}]

So you can think of 35+36+37+38.....+145+146+150 as (1+2+3+...+35+36+37+38+.....+145+146+150)-(1+2+3+...+33+34) and apply the formula given above. Let me know if this helps at all.