The resistance is 16 ohm's
V=I x R where V is the voltage, I is the current, and R is the resistance in Ohms
120= 15 x R
R=120/15
R= 8 Ohm's
P=VxV / R
P=120v x 120v / 8 ohms
P= 14400/8
P = 1800 watts
R = V x V/P
R = 14400/900
R = 16 Ohm's
The resistance is 16 ohm's:
I = V/R
I = 120/16
I = 7.5 Amps