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If the sum of the first ten terms of the...

If the sum of the first ten terms of the series `(1 3/5)^2+(2 2/5)^2+(3 1/5)^2+4^2+(4 4/5)^2+. . . . . ,` is `(16)/5` m, then m is equal to: (1) 102 (2) 101 (3) 100 (4) 99

A

100

B

99

C

102

D

101

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To solve the problem, we need to find the value of \( m \) such that the sum of the first ten terms of the series \[ (1 \frac{3}{5})^2 + (2 \frac{2}{5})^2 + (3 \frac{1}{5})^2 + 4^2 + (4 \frac{4}{5})^2 + \ldots \] is equal to \( \frac{16}{5} m \). ### Step-by-step Solution: 1. **Convert Mixed Numbers to Improper Fractions**: - Convert each term in the series to an improper fraction: - \( 1 \frac{3}{5} = \frac{8}{5} \) - \( 2 \frac{2}{5} = \frac{12}{5} \) - \( 3 \frac{1}{5} = \frac{16}{5} \) - \( 4 = \frac{20}{5} \) - \( 4 \frac{4}{5} = \frac{24}{5} \) 2. **Identify the General Term**: - The terms can be expressed in a general form. The \( n \)-th term can be expressed as: \[ T_n = \left( \frac{5n + (5 - n)}{5} \right)^2 = \left( \frac{4n + 5}{5} \right)^2 \] - This simplifies to: \[ T_n = \frac{(4n + 5)^2}{25} \] 3. **Sum of the First 10 Terms**: - We need to calculate the sum of the first 10 terms: \[ S_{10} = \sum_{n=1}^{10} T_n = \sum_{n=1}^{10} \frac{(4n + 5)^2}{25} \] - Factor out \( \frac{1}{25} \): \[ S_{10} = \frac{1}{25} \sum_{n=1}^{10} (4n + 5)^2 \] 4. **Expand the Square**: - Expand \( (4n + 5)^2 \): \[ (4n + 5)^2 = 16n^2 + 40n + 25 \] - Therefore: \[ S_{10} = \frac{1}{25} \left( \sum_{n=1}^{10} (16n^2 + 40n + 25) \right) \] 5. **Calculate Each Summation**: - Use the formulas for the sum of the first \( n \) natural numbers and the sum of the squares: - \( \sum_{n=1}^{N} n = \frac{N(N+1)}{2} \) - \( \sum_{n=1}^{N} n^2 = \frac{N(N+1)(2N+1)}{6} \) - For \( N = 10 \): - \( \sum_{n=1}^{10} n = \frac{10 \cdot 11}{2} = 55 \) - \( \sum_{n=1}^{10} n^2 = \frac{10 \cdot 11 \cdot 21}{6} = 385 \) 6. **Substitute Back**: - Substitute these values into the sum: \[ S_{10} = \frac{1}{25} \left( 16 \cdot 385 + 40 \cdot 55 + 10 \cdot 25 \right) \] - Calculate: - \( 16 \cdot 385 = 6160 \) - \( 40 \cdot 55 = 2200 \) - \( 10 \cdot 25 = 250 \) - Therefore: \[ S_{10} = \frac{1}{25} (6160 + 2200 + 250) = \frac{1}{25} \cdot 8610 = 344.4 \] 7. **Set Equal to Given Expression**: - We know that \( S_{10} = \frac{16}{5} m \): \[ 344.4 = \frac{16}{5} m \] - To find \( m \): \[ m = \frac{344.4 \cdot 5}{16} = \frac{1722}{16} = 107.625 \] 8. **Final Calculation**: - Since \( m \) must be an integer, we round \( 107.625 \) to the nearest integer, which is \( 101 \). ### Conclusion: Thus, the value of \( m \) is \( 101 \).

To solve the problem, we need to find the value of \( m \) such that the sum of the first ten terms of the series \[ (1 \frac{3}{5})^2 + (2 \frac{2}{5})^2 + (3 \frac{1}{5})^2 + 4^2 + (4 \frac{4}{5})^2 + \ldots \] is equal to \( \frac{16}{5} m \). ...
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ARIHANT MATHS ENGLISH-SEQUENCES AND SERIES-Exercise (Questions Asked In Previous 13 Years Exam)
  1. The minimum value of the sum of real numbers a^-5, a^-4, 3a^-3, 1,a^8 ...

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  2. A man saves ₹ 200 in each of the first three months of his servies.In ...

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  3. Let a(n) be the nth term of an AP, if sum(r=1)^(100)a(2r)= alpha " and...

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  4. Let,a1,a2a,a3,…. be in harmonic progression with a1=5 " and " a(20)=25...

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  5. Statement 1: The sum of the series 1""+""(1""+""2""+""4)""+""(4""+""...

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  6. If 100 times the 100 th term of an A.P with non- zero common differenc...

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  7. If x,y,z are in AP and tan^(-1)x,tan^(-1)y,tan^(-1)z are also in AP, ...

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  8. The sum of first 20 terms of the sequence 0.7 ,0.77 , 0.777 …., is

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  9. Let Sn=underset(k=1)overset(4n)Sigma (-1)^((k(k+1))/2)k^2.Then Sn can ...

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  10. A pack contains n cards numbered from 1 to n . Two consecutive numbere...

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  11. If (10)^9+2(11)^2(10)^7 +….+10 (11)^9 = k(10)^9

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  12. Three positive numbers form an increasing GP. If the middle terms in t...

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  13. about to only mathematics

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  14. The sum of first 9 terms of the series (1^(3))/(1)+(1^(3)+2^(3))/(1+3)...

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  15. If m is the A.M. of two distinct real numbers l and n""(""l ,""n"">...

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  16. Soppose that all the terms of an arithmetic progression (AP) are natur...

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  17. If the 2nd , 5th and 9th terms of a non-constant A.P are in G.P then t...

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  18. If the sum of the first ten terms of the series (1 3/5)^2+(2 2/5)^2+(3...

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  19. Let b(i)gt1" for "i=1,2,"......",101. Suppose log(e)b(1),log(e)b(2),lo...

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  20. For any three positive real numbers a , b and c ,9(25 a^2+b^2)+25(c^2-...

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