The sum of the first 12 terms of an A P whose first term and fourth term are 8 and 14 respectively i...........

Quantitative Aptitude (CDS) Arithmetic progression

The sum of the first 12 terms of an A.P. whose first term and fourth term are 8 and 14 respectively is?

210

230

200

228

first term a=8
4th term=a+(4-1)d
14=8+3d
d=2
sum of 13 term is=12/2(2×8+11 × 2)
=6(16+22)
=228

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