JEE Mains · Maths · STD 11 - 8. sequence and series
Let \(3, a, b, c\) be in \(A.P.\) and \(3, a-1, b+1, c+9\) be in \(G.P.\) Then, the arithmetic mean of \(a, b\) and \(c\) is :
- A \(-4\)
- B \(-1\)
- C \(13\)
- D \(11\)
Answer & Solution
Correct Answer
(D) \(11\)
Step-by-step Solution
Detailed explanation
\(3, \mathrm{a}, \mathrm{b}, \mathrm{c} \rightarrow \mathrm{A} . \mathrm{P} \quad \Rightarrow 3,3+\mathrm{d}, 3+2 \mathrm{~d}, 3+3 \mathrm{~d}\)…
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