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Which term of the AP 3, 15, 27, 34, ……. will be 132 more than its 54th term? |
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Answer» Given, AP is 3, 15, 27, 34, ……. First term of AP is a = 3 and common difference of AP is d = a2 – a1 = 15 – 3 = 12. 54th term of AP is a54 = a + (54 – 1)d (∵ an = a + (n – 1) d and n = 54) = 3 + 53 × 12 = 3 + 636 = 639. (∵ a = 3 & d = 12) Let nth term of AP is 132 more than its 54th term. i.e., an = 132 + a54 = 132 + 639 = 771 ⇒ 3 + (n – 1) 12 = 771 (∵ a = 3 & d = 12 and an = a + (n – 1) d) ⇒ 12(n − 1) = 771 − 3 = 768 ⇒ n − 1 = \(\frac{768 }{12}\) = 64 ⇒ n = 64 + 1 = 65. Hence, 65th term of AP is 132 more than its 54th term. Given a = 3, d = 12, n = 54. = 3 + (54-1) * 12 a54 = 639. Given that the term is 132 more than its 54th term = 639 + 132 = 771. Therefore the 65th term is 132 more than its 54th term.Given a = 3, d = 12, n = 54. Given that the term is 132 more than its 54th term = 639 + 132 = 771. |
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