InterviewSolution
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InterviewSolution
| 1. |
Which term of gp 18,-12,8....is512/729 |
| Answer» Let the first term be \'a\'The common difference be \'r\'nth term is = a*r^(n-1)Sofirst terma1 = a*r^0a = 18second term\xa0a2 = a*r^1 = -12hence r = -2/3Third term\xa0a3 = 18*(-2/3)^2 = 8Hence\xa0a = 18r = -2/3512/729 = 18*(-2/3)^n -------(1)after cross multiplying 18 we have to find the power of n which satisfies (-2/3)^n = 256/6561we obtain (-2)^8 = 256 and 3^8 = 6561therefore (1) becomes18*(-2/3)^8 = 512/729n-1 = 8Therefore it is the 9th term | |