JEE Mains · Maths · STD 11 - 8. sequence and series
Five numbers are in \(A.P.\), whose sum is \(25\) and product is \(2520 .\) If one of these five numbers is \(-\frac{1}{2},\) then the greatest number amongst them is
- A \(\frac{21}{2}\)
- B \(27\)
- C \(16\)
- D \(7\)
Answer & Solution
Correct Answer
(C) \(16\)
Step-by-step Solution
Detailed explanation
Let the A.P is \(a-2 d, a-d, a, a+d, a+2 d\) \(\because \operatorname{sum}=25 \Rightarrow \mathrm{a}=5\) Product \(=2520\) \(\left(25-4 d^{2}\right)\left(25-d^{2}\right)=504\) \(4 \mathrm{d}^{4}-125 \mathrm{d}^{2}+121=0\) \(\Rightarrow \mathrm{d}^{2}=1, \frac{121}{4}\)…
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