How do I figure out the fraction of the period, thanks!

6=. 3s for oneway C . 625 +12 1.6 5. A machine part is undergoing SHM with a frequency of 5.00 Hz and amplitude 1.80 cm. How long does it take the part to go from x = 0 to x = -1.80 cm? [Hint: find the period. Then figure out what fraction of a period we are talking about.] f = 5. Hz