Question

find the sum of the series3+7+11 ------- to 10 terms​

Answer 1

Answer:

a = 3

d = 7-3 = 4

n = 10

Sn = (n/2) 2a+(n-1)d

S10 = (10/2 2(3) + (10-1)4

S10 = 5 (6+(9)4)

S10 = 5 (6+36)

S10 = 210