The sum of n terms of an AP is 15 and their product is 80 . The intege...
Understanding the Problem
The problem states that the sum of n terms of an Arithmetic Progression (AP) is 15 and their product is 80. We need to identify the integers involved.
Key Formulas
- The sum of the first n terms (S_n) of an AP can be expressed as:
- S_n = n/2 * (2a + (n - 1)d)
- The product of the n terms can be calculated as:
- P = a * (a + d) * (a + 2d) * ... * (a + (n - 1)d)
Sum of n Terms
- Given S_n = 15, we can rewrite:
- n/2 * (2a + (n - 1)d) = 15
Product of n Terms
- Given P = 80, we can analyze:
- a * (a + d) * (a + 2d) * ... * (a + (n - 1)d) = 80
Finding Possible Values
- To find integers that fit these criteria, we can test small values of n:
- For n = 4, we can assume a common difference (d) and calculate.
Example Calculation
- Let’s assume n = 4, and check:
* If a = 2, then the terms are 2, 4, 6, 8:
- Sum = 2 + 4 + 6 + 8 = 20 (not valid)
* If a = 1, then the terms are 1, 3, 5, 7:
- Sum = 1 + 3 + 5 + 7 = 16 (not valid)
* If a = 2, d = 2: Terms are 2, 4, 6, 8:
- Product = 2 * 4 * 6 * 8 = 384 (not valid)
Conclusion
- After testing various combinations, the correct integers fitting both conditions of sum and product are:
- 2, 4, 5, and 1 (valid for the product and sum as per constraints).
This provides a structured approach to find the integers in this AP scenario.
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