JEE Mains · Maths · STD 11 - 6. permutation and combination
The number of \(3-\)digit numbers, formed using the digits \(2,3,4,5\) and \(7\) , when the repetition of digits is not allowed, and which are not divisible by \(3\) , is equal to ..........
- A \(10\)
- B \(41\)
- C \(25\)
- D \(36\)
Answer & Solution
Correct Answer
(D) \(36\)
Step-by-step Solution
Detailed explanation
\(2,3,4,5,7\) total number of three digit numbers not divisible by \(3\) will be formed by using the digits \( (4,5,7) \) \( (3,4,7) \) \( (2,5,7) \) \( (2,4,7) \) \( (2,4,5) \) \( (2,3,5) \) number of ways \(=6 \times 3 !=36\)
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