A 1650W hair drier is plugged into a 110V outlet, how much resistance does it have?

7.33333

Explanation:

The voltage V in volts (V) is equal to the current I in amps (A) times the impedance Z in ohms (Ω):

V (V) = I (A) * Z (Ω) = (|I|*|Z|) ∠ (θI + θZ)

The complex power S in volt-amps (VA) is equal to the voltage V in volts (V) times the current I in amps (A):

S (VA) = V (V) * I (A) = (|V|*|I|) ∠ (θV - θI)