Question

what is the sum of the last four terms of the series 97+99+101+ . . . + 121?

Answer 1

as the sum tends to 4 terms so 121+119+117+115=472:)
othewise use Sn=n/2[a+l] where n=4 a=121 and l=115:)

Answer 2

97+2=99
99+2=101
101+2= 103
103+2=105
105+2= 107
107+2= 109
109+2=111
111+2= 113
113+2=115
115+2=117
117+2= 119
119+2=121

115+117+119+121= 472

Answer 3

ohhh, okay haha wow, i feel dumb.

Answer 4

no dnt feel sometimes it just happens:)

Answer 5

Dont, some things you just dont know, but now you've learned.