I was going through my chapter i have a question as Find sum of first 22 terms of an AP in which d =7 and 22nd term is 149
d = 7
a22 = 149
n=22 s22 = ?
an = a + (n - 1 ) d
149 = a + ( 22 - 1) 7
149 = a + 147
a = 2
From where we can say that an = 149 for reference my chapter book is http://www.youtube.com/watch?v=j3AcMEc2t-A