Question

there are 5 lamps in hall. each one can be switched on independently . number of ways hall can be illuminated
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Answer 1

Answer:

15

Step-by-step explanation:

lamp 1

lamp 2

lamp 3

lamp 4

lamp 5

1 and 2

1 and 3

1 and 4

1 and 5

2 and 3

2 and 4

2 and 5

3 and 4

3 and 5

4 and 5