Construct a truth table to determine when the lightbulb is on. That is, determine which switches must be open and which switches must be closed for the lightbulb to be on. 
A. The lightbulb will be on when p, q, and r are all closed; when p and q are closed and r is open; or when p and r are closed and q is open.
B. The lightbulb will be on when p, q, and r are all closed; when p and q are closed and r is open; when p and r are closed and q is open; or when p is closed and q and r are open.
C. The lightbulb will be on in all cases except when p and r are open and q is closed.
D. The lightbulb will be on when p and r are closed and q is open.
Answer: B
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A. 
B. 1
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D. - 
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A. 4e?(sin ? - cos ?) + 4e? B. 0 C. 8e?(sin ? - cos ?) D. 8e? sin ?
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? 
A. 5
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C. 10
D. 
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A. - 
B. 
C. -
D. 