Answer
$3725$
Work Step by Step
As we are given that $\sum_{i=1}^{50}(3i-2)$
Now, terms will be {$1,4,7,10,...,148$}; this implies that it shows an arithmetic sequence.
whose sum will be $S_{50}=\dfrac{n}{2}(a_1+a_n)=\dfrac{50}{2}(1+148)=25(149)$
Finally, $S_{50}=3725$
