Find the sums given below :
34 + 32 + 30 + . . . + 10
Advertisement Remove all ads
Solution
34 + 32 + 30 + ……….. + 10
For this A.P.,
a = 34
d = a2 − a1 = 32 − 34 = −2
l = 10
Let 10 be the nth term of this A.P.
l = a + (n − 1) d
10 = 34 + (n − 1) (−2)
−24 = (n − 1) (−2)
12 = n − 1
n = 13
`S_n = n/2(a+1)`
`=13/2(34+10)`
`=(13xx44)/2 = 13 xx 22`
= 286
Concept: Sum of First n Terms of an AP
Is there an error in this question or solution?
Advertisement Remove all ads
APPEARS IN
Advertisement Remove all ads
Advertisement Remove all ads