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An AP consists of 50terms of which 3rd term is 12 and the last term is 106. Find the 29th term. |
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Answer» Let a , d are first term and commondifference of an A.Pnth term = Last term = a + ( n - 1 )dan = a + ( n - 1 )dNow ,It is given that ,Third term = 12a + 2d = 12 ------( 1 )Last term = 106a + 49d = 106 ---( 2 )Subtract ( 1 ) from ( 2 ) , we get47d = 94d = 2Substitute d value in equation ( 1 ) ,We geta + 2 × 2 = 12a = 12 - 4a = 829th term = a + 28da29 = 8 + 28 × 2= 8 + 56= 64 n=50 a+2d=12 - - - - 1 a49d106 - - - - - 2 by 2-1 we get, a+47d-a-2d= 106-12 47d=94 D=94/47 d=2 then a=8 a+(n-1)d=nth term 8+28×2=64 |
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