Question

An A.P consists of 23 terms.If the sum of the 3 terms in the middle is 141 and the sum of last 3 terms is 261, then the first term is :

Answer 1

Solution :
a11+a12+a13=141=>3a+33d=141=>a+11d=47
a21+a22+a23=261=>3a+63d=261=>a+21d=87
on solving : a=3
Answer : 3
answered Jan 27, 2016 by meena.p