Answer
Sum $S_{50}$ = 3725
Work Step by Step
Put i = 1 to 50 in (3i - 2)
First term (i = 1) $a_{1}$ = (3$\times$1 - 2) = 1
Second term (i = 2) $a_{2}$ = (3$\times$2 - 2) = 4
Third term (i = 3) $a_{3}$ = (3$\times$3 - 2) = 7
Fourth term (i = 4) $a_{4}$ = (3$\times$4 - 2) = 10
$50^{th}$ term = (3$\times$50 - 2) = 148
From above we observe that the sequence (1, 4, 7, 10 ........148) is a arithmetic sequence with common difference = 3
Sum $S_{50}$ = $\frac{50}{2}$(1 + 148) = 25$\times$149 = 3725
