SOLUTION: Two persons are to run a race but one can run 12 meters per second, whereas the other can run 6 meters per second. If the slower runner has a 93- meter head start,how long will it

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Question 939886: Two persons are to run a race but one can run 12 meters per second, whereas the other can run 6 meters per second. If the slower runner has a 93- meter head start,how long will it be before the faster runner catches the slower runner, if they begin at the same time?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Start a stop watch when they both start running
Let +t+ = the time in seconds on the stopwatch
when the faster runner catches the slower runner
Let +d+ = the distance the faster runner
travels until they meet
---------------------------------------
Slower runner's equation:
(1) +d+-+93+=+6t+
Faster runner's equation:
(2) +d+=+12t+
----------------------
Substitute (2) into (1)
(1) +12t+-+93+=+6t+
(1) +6t+=+93+
(1) +t+=+15.5+
The faster runner catches the slower runner in 15.5 sec
check:
(1) +d+-+93+=+6%2A15.5+
(1) +d+=+93+%2B+93+
(1) +d+=+186+ m
and
(2) +d+=+12%2A15.5+
(2) +d+=+186+ m
OK