Your book's answer is correct. Since you did not show how you got your answer it is impossible to say what you might have done wrong.
A watch, which gains 5 seconds every 3 minutes, is set right at 6a.m. What is the true time in the afternoon of the same day when the watch indicates a quarter past 3?
My answer is 2:59:15 seconds but the book answer is 3:00:00
Kindly check if you get a chance, appreciate your help.
@HallsOf Ivy I did similiar to bjhopper
the difference between 6 a.m to 3:15 pm is 9 hours and 15 minutes which is equal to 555 minutes.
So we have 555/3 = 185 minutes, which is equal to 185 * 5= 925 seconds or 15 minutes and 25 seconds. So I get 2:59:35.