Answer
Input current = 0.36 A.
Work Step by Step
Electric power is the same in both the primary and secondary coils. Power is the product of current, I, and voltage, V.
$$(I \times V)_{primary}= (I \times V)_{secondary} $$
$$(I)(120 V)= (1.8 A)(24 V)$$
Solve for the input current of 0.36 A.