Q9 of 67 Page 69

There are 60 terms in an arithmetic progression. If its first and last term are respectively 7 and 125, then find its 32th term.

Given, a = 7 and a60 = 125.
∴ an = a + (n – 1)d


Where,


a = First term of AP
d = Common difference of AP
and no of terms is ‘n’



⇒ a60 = 7 + (60 - 1)d
⇒ 125 = 7 + (59)d
⇒ 118 = 59 × d
⇒ d = 2


Now 32th term, a32 = a + (32 - 1)d


= 7 + 31 × 2
= 7 + 62
= 69


Hence, 32th term is 69.


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