Question

Sum of 15 terms of series S= 2 + 5 + 8 + 11 +
...is
​

Answer 1

Answer:

Step-by-step explanation:

Sn =  2 n ×[2a+(n−1)d],

n=15,a=2,d=3,

S n =  2 15 ×[2×2+(15−1)3],

Sn=345