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प्रश्न
Find the 9th term from the end (towards the first term) of the A.P. 5, 9, 13, ...., 185
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उत्तर
Common difference, d, of the AP = 9 − 5 = 4
Last term, l, of the AP = 185
We know that the nth term from the end of an AP is given by l − (n − 1)d.
Thus, the 9th term from the end is
185 − (9 − 1)4
= 185 − 4 × 8
= 185 − 32
= 153
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