Which term of the A.P. 14, 9, 4, – I, – 6, ... is – 41 ?

1.	Which term of the A.P. 14, 9, 4, – I, – 6, ... is – 41 ?
Answer» Here, a = 14, d = 9 – 14 = –5 and a_n = –41 To find : n We have, a_n = a + (n – 1)d ⇒ –41 = 14 + (n – 1) × (–5) ⇒ –41 = 14 – 5n + 5 ⇒ –41 = 19 – 5n ⇒ – 41 – 19 = –5n ⇒ –60 = –5n ⇒ n = 12 Therefore, the 12^th term of the given AP is –41.

Answer»

Here, a = 14, d = 9 – 14 = –5 and a_n = –41

To find : n

We have,

a_n = a + (n – 1)d

⇒ –41 = 14 + (n – 1) × (–5)

⇒ –41 = 14 – 5n + 5

⇒ –41 = 19 – 5n

⇒ – 41 – 19 = –5n

⇒ –60 = –5n

⇒ n = 12

Therefore, the 12^th term of the given AP is –41.

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