DAY 323

A watch gains 5 seconds every 3 minutes. It is set correctly at 7:00 am. That afternoon the watch read 4:15. What was the correct time?

Answer:

4:00............ 7:00 am to 4:15 pm = 9 hours and 15 minutes, or 555 minutes. For every 3 minute and 5 second interval in that time, the time shown on the watch is 5 seconds fast. For example, at correct time 4:03, the watch shows 4:03 and 5 seconds. Five seconds = 1/12 minute.

555 divided by 3 1/12 = 180 intervals

180 X 5 = 900 seconds

900/60 = 15 minutes (fast)