JEE MATHEMATICS MCQ: PERMUTATIONS

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In a certain city, all telephone numbers have six digits, the first two digits always being 41 or 42 or 46 or 62 or 64 . The number of telephone numbers having all six digits distinct is

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Correct option: A

8400

Option A (8400) is correct because it calculates the number of distinct telephone numbers for each possible starting pair and then multiplies by the number of starting pairs.

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