Find the sum of 12 terms of an A.P. whose nth term is tn = 3n + 4
262
272
282
292
Answers
Answered by
5
Answer:
282
Step-by-step explanation:
in an A.P.
T(n)=3n+4 putting n=1,2,3,- - - -,we get
7,10,13,16,- - - Are in A.P.
First term a=7,d=3.
S(n)= n/2{2a+ (n-1)d}
s(12) =12/2{2×7+(12–1)3}
=6{14+33}
=6×47
=282.
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