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The sum of first n terms of an AP is 5n^...

The sum of first n terms of an AP is `5n^2 + 3n` If its mth term is 168, find the value of m. Also find the 20th term of the AP.

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The correct Answer is:
`m=17 ,a_(20)=198`
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KUMAR PRAKASHAN-ARITHMETIC PROGRESSION-PRACTICE THOROUGHLY
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  2. Find the sum of following AP: (x-y)^2, (x^2+y^2),(x+y)^(2), ..........

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  3. Find the sum of following AP: (x-y)/(x+y),(3x-2y)/(x+y),(5x-3y)/(x+y...

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  4. How many terms of the AP 27, 24, 21, ... should be taken so that their...

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  5. Find the sum of all three digit numbers which are multiples of 11.

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  6. In an AP, the sum of first ten terms is - 150 and the sum of its next ...

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  7. Show that the sum of all odd integers between 1 and 1000 which are div...

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  8. A thief, after committing a theft runs at a uniform speed of 50 m/minu...

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  9. The sum of first n terms of three APs are S1, S2 and S3. The first ter...

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  10. The sum of first n terms of an AP is 5n^2 + 3n If its mth term is 168...

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  11. Solve the equation : (-4)+(-1)+2+5+........+x=437

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  12. Fill in the blanks so as to make each of the following statements true...

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  17. Answer each question by selecting the proper alternative from those gi...

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  19. Answer each question by selecting the proper alternative from those gi...

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  20. Answer each question by selecting the proper alternative from those gi...

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