JEE Mains · Maths · STD 11 - 6. permutation and combination
The number of ways, \(16\) identical cubes, of which \(11\) are blue and rest are red, can be placed in a row so that between any two red cubes there should be at least \(2\) blue cubes, is
- A \(56\)
- B \(66\)
- C \(76\)
- D \(86\)
Answer & Solution
Correct Answer
(A) \(56\)
Step-by-step Solution
Detailed explanation
\(x_{1}+x_{2}+x_{3}+x_{4}+x_{5}+x_{6}=11\) \(x_{1}, x_{6} \geq 0, \quad x_{2}, x_{3}, x_{4}, x_{5} \geq 2\) \(x_{2}=t_{1}+2\) \(x_{3}=t_{3}+2\) \(x_{4}=t_{4}+2\) \(x_{5}=t_{5}+2\) \(x_{1}, t_{2}, t_{3}, t_{4}, t_{5}, x_{6} \geq 0\) No. of solutions…
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