Question

A watch which gains 5 seconds in 3 min. was set right at 7 : 00 a.m. In the afternoon of the same day, when the watch indicated quarter past 4 O'clock the true time is :
(1) 4 : 05 P.M. .
(2) 4 : 00 P.M.
(3) 3 : 45 P.M.
(4) 4 : 10 P.M

Answer 1

Clock gains 5 seconds every 3 minutes = 100 seconds every hour (60 minutes) = 900 seconds every 9 hours = 15 minutes every 9 hours.
Hence when the faulty clock shows 4:15 PM, the actual clock should show 15 minutes less i.e. 4:00 PM