Answer:
Sum of last four term is 472.
Explanation:
Given : 97+99+101+....+121.
To find : what is the sum of the last four terms .
Solution : We have given that 97+99+101+....+121.
Common difference = second term - first term
Common difference = 99 - 97 = 2
Then , fourth term 101 + 2 = 103
Fifth term 103 + 2 = 105
Sixth term 105 + 2 = 107
107 + 2 = 109
109 + 2 = 111
111+2 = 113
113 + 2 = 115
115 + 2 = 117
117 + 2 = 119
119 +2 = 121
Then last four terms are 115 , 117, 119, 121.
Then, S = 115 + 117 + 119 +121
S = 472
Therefore, Sum of last four term is 472.