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If the sums of n terms of two Aps are in...

If the sums of n terms of two Aps are in the ratio ( 2n+3) :(3n+2) , find the ratio of their 10th terms.

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To solve the problem, we need to find the ratio of the 10th terms of two arithmetic progressions (APs) given that the sums of their first n terms are in the ratio (2n + 3) : (3n + 2). ### Step-by-Step Solution: 1. **Understanding the Sum of n Terms of an AP**: The sum of the first n terms \( S_n \) of an AP can be expressed as: \[ S_n = \frac{n}{2} \left(2A + (n-1)D\right) \] where \( A \) is the first term and \( D \) is the common difference. 2. **Set Up the Sums for Two APs**: Let’s denote the first AP by \( A_1 \) and \( D_1 \), and the second AP by \( A_2 \) and \( D_2 \). - For the first AP: \[ S_{n1} = \frac{n}{2} \left(2A_1 + (n-1)D_1\right) \] - For the second AP: \[ S_{n2} = \frac{n}{2} \left(2A_2 + (n-1)D_2\right) \] 3. **Form the Ratio of the Sums**: According to the problem, the ratio of the sums of the first n terms of the two APs is given by: \[ \frac{S_{n1}}{S_{n2}} = \frac{2n + 3}{3n + 2} \] Canceling \( \frac{n}{2} \) from both sides gives: \[ \frac{2A_1 + (n-1)D_1}{2A_2 + (n-1)D_2} = \frac{2n + 3}{3n + 2} \] 4. **Cross-Multiplying**: Cross-multiplying gives: \[ (2A_1 + (n-1)D_1)(3n + 2) = (2A_2 + (n-1)D_2)(2n + 3) \] 5. **Finding the 10th Terms**: The 10th term of an AP can be expressed as: \[ T_{10} = A + 9D \] Therefore, we need to find the ratio: \[ \frac{T_{10,1}}{T_{10,2}} = \frac{A_1 + 9D_1}{A_2 + 9D_2} \] 6. **Substituting for n = 19**: To find the ratio of the 10th terms, we can set \( n = 19 \) (since \( N - 1 = 18 \) gives us \( N = 19 \)): - Substitute \( n = 19 \) into the ratio of sums: \[ \frac{2(19) + 3}{3(19) + 2} = \frac{41}{59} \] 7. **Final Ratio of 10th Terms**: Thus, the ratio of the 10th terms of the two APs is: \[ \frac{A_1 + 9D_1}{A_2 + 9D_2} = \frac{41}{59} \] ### Conclusion: The ratio of the 10th terms of the two APs is \( 41 : 59 \).

To solve the problem, we need to find the ratio of the 10th terms of two arithmetic progressions (APs) given that the sums of their first n terms are in the ratio (2n + 3) : (3n + 2). ### Step-by-Step Solution: 1. **Understanding the Sum of n Terms of an AP**: The sum of the first n terms \( S_n \) of an AP can be expressed as: \[ S_n = \frac{n}{2} \left(2A + (n-1)D\right) ...
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