Q15 of 85 Page 110

For A.P. T18 — T8 = ………

We know that, Tn = a + (n – 1)d


So we have, T18= a + (18 – 1)d


⇒ T18= a + 17d


Now T8= a + (8 – 1)d


⇒ T8= a + 7d


Now we have,


⇒ T18 — T8 = [a + 17d] – [a + 7d]


= 10d


∴ the correct option is (b)

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