Q12 of 67 Page 74

Which term of the arithmetic progression is the first negative term ?

Here, first term a = 20 and common difference d We know that general term an = a + (n - 1)d


Where,


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



Since the common difference is negative we get the first negative term when -(n - 1)d > a


⇒ (n - 1) > 26.66
⇒ n > 26.66 + 1
⇒ n > 27.66
⇒ n = 28


Hence, 28th term of the arithmetic progression is first negative term.


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