At the precise instant when Mr. Ifield drove off from his residence in his car at a constant speed of 44 miles per hour; the minute hand of his 12 hour analog wristwatch was precisely on a minute mark.
After 3 miles of travel, Mr. Ifield stopped by a gasoline station to refuel when he observed that the minute hand and the hour hand of his wrist watch were exactly coincident but the minute hand was not precisely situated on a minute mark.
At what time did Mr. Ifield leave his residence?
(In reply to solution
Three miles at 44 mph takes 4 1/11 minutes.
The hour and minute hand are together every 12/11 hours, or 1 hr, 5 5/11 min. We need the fractional minutes to be 1/11, so that 4 1/11 min before, it would have been an even minute.
9 * 5/11 = 45/11 so the fractional part would be 1/11.
9 * (1 hr, 5 5/11 min) = 9 hr 49 1/11 min.
Subtract 4 1/11 min to get 9:45.
Posted by Charlie
on 2006-12-08 10:24:30