WBJEE · Maths · Binomial Theorem
The number of irrational terms in the binomial expansion of \(\left(3^{1 / 5}+7^{1 / 3}\right)^{100}\) is
- A 90
- B 88
- C 93
- D 94
Answer & Solution
Correct Answer
(D) 94
Step-by-step Solution
Detailed explanation
General term of \(\left(3^{1 / 5}+7^{1 / 3}\right)^{100}\) is given by \(T_{\gamma+1}={ }^{100} C_{r}\left(3^{1 / 5}\right)^{100-r}\left(7^{1 / 3}\right)^{r}\) \(={ }^{100} C_{1} \cdot 3^{\frac{100-r}{5}} \cdot 7^{\frac{r}{3}}\) For a rational term. \(\frac{100-r}{5}\) and…
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