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JEE MATHEMATICS MCQ: PERMUTATIONS

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Every one of the 10 available lamps can be switched on to illuminate certain Hall. The total number of ways in which the hall can be illuminated, is

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Correct option: B

1023

Option B,

1023

, is correct because each lamp can be either on or off, giving

2^{10}

possibilities, but we must subtract 1 for the case where all lamps are off.

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