A transformer for an answering machine takes an ac voltage of amplitude 170 V as its input

Question:

A transformer for an answering machine takes an ac voltage of amplitude 170 V as its input and supplies a 7.8-V amplitude to the answering machine. The primary has 300 turns.
(a) How many turns does the secondary have?
(b) When idle, the answering machine uses a maximum power of 5.0 W. What is the amplitude of the current drawn from the 170-V line?