JEE Mains · Maths · STD 11 - 14. probability
If the probability that a randomly chosen \(6\)-digit number formed by using digits \(1\) and \(8\) only is a multiple of \(21\) is \(p\), then \(96\;p\) is equal to
- A \(30\)
- B \(33\)
- C \(40\)
- D \(43\)
Answer & Solution
Correct Answer
(B) \(33\)
Step-by-step Solution
Detailed explanation
\(2 \;\times\; 2 \;\times \;2 \;\times \;2\; \times \;2 \;\times \;2\;=\;64\) Divisible by \(21\) when divided by \(3\) . Case - \(I\) : All \(1 \rightarrow\) \((1)\) Case - \(II\) : All \(8 \rightarrow\) \((1)\) Case - \(III\) : \(3\) ones and \(3\) eights…
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