WBJEE · Maths · Basic of Mathematics
If \(\log _7 2=\lambda\), then the value of \(\log _{49}(28)\) is
- A \((2 \lambda+1)\)
- B \((2 \lambda+3)\)
- C \(\frac{1}{2}(2 \lambda+1)\)
- D \(2(2 \lambda+1)\)
Answer & Solution
Correct Answer
(C) \(\frac{1}{2}(2 \lambda+1)\)
Step-by-step Solution
Detailed explanation
Hints: \(\log _{49} 28=\log _{72} 4 \times 7\) \(=\frac{1}{2}\left[2 \log _7 2+\log _7 7\right]=\frac{1}{2}[2 \lambda+1]\)
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