Find the sum 1 + 3 + 5 +........+ 21.
Answers
Answered by
1
Answer:
Hiii kavya....
can u tell ur instagram name or.. take my insta name from my profile
Step-by-step explanation:
It form an A.P
a = 1
d = 2
L = 21
L = a + (n -1 )d
21 = 1 + (n - 1 ) 2
20/2 = n -1
n = 11
Sn = n/2[ a + L ]
= 11/2 [ 1 + 21]
= 11/2 × 22
= 11 × 11
= 121
Therfore sum of this given terms is 121
Similar questions