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Question
How many terms are there in the AP 41, 38, 35, ….,8?
Solution
In the given AP, a = 41 and d = (38-41) = -3
Suppose that there are n terms in the given AP.
Then Tn = 8
⇒ a + (n-1) d = 8
⇒ 41+ (n-1) × (-3) = 8
⇒ 44- 3n =8
⇒ 3n = 36
⇒ n=12
Hence, there are 12 terms in the given AP.
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