If a baseball pitcher throws a fastball at a horizontal speed of 160km/h how long does it take to reach home plate 18.4m away?

In the book it shows 414ms as the answer but I can't get that answer.I divided 18.4 by 160 and got 115

You much change the units so they match. The 160 is kILOMETERS/HR and the plate is 18.4 METERS.
Then the anwer will have hours as the time and you much change that to sec, then to ms. I hope this helps.

distance= velocty*time

solve for time. change 160km/hr to m/s

A neat way to do this is to paste this in your google search window.
160km/hr to m/s

Then if you really want to be cool, solve for time directly this way by pasting this in the google search engine:

18.4m/160km/hr in msec

OR, just go to google and type in 18.4 meters/160 km/hr = and it converts before deviding and gives 0.414 seconds. Neat.