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JEE Mains · Maths · STD 11 - 7. binomial theoram

If the coefficient of \(\mathrm{a}^{7} \mathrm{~b}^{8}\) in the expansion of \((a+2 b+4 a b)^{10}\) is \(K \cdot 2^{16}\), then \(K\) is equal .... .

  1. A \(315\)
  2. B \(123\)
  3. C \(745\)
  4. D \(96\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(315\)

Step-by-step Solution

Detailed explanation

\(\frac{10 !}{\alpha ! \beta ! \gamma !} \mathrm{a}^{\alpha}(2 \mathrm{~b})^{\beta} \cdot(4 \mathrm{ab})^{\gamma}\) \(\frac{10 !}{\alpha ! \beta ! \gamma !} \mathrm{a}^{\alpha+\gamma} \cdot \mathrm{b}^{\beta+\gamma} \cdot 2^{\beta} \cdot 4^{\gamma}\)…