SOLUTION: Mary and Murray travel respectively at x and y km/h heading directly towards each other across a distance of 240km. If both start at 9 a.m. they will meet at noon. If Murray starts

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Question 1126195: Mary and Murray travel respectively at x and y km/h heading directly towards each other across a distance of 240km. If both start at 9 a.m. they will meet at noon. If Murray starts at 9 a.m. they and Mary starts at 10 a.m. they will meet soon at 12:30 p.m. Find (x,y).
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
dd their speeds since they travel towards each other
(1) +240+=+%28+x+%2B+y+%29%2A3+
Next Murray gets a 1 hr head start. In 1 hr, he travels:
+d%5B1%5D+=+y%2A1+ km
Start counting time when Mary leaves
(2) +240+-+y+=+%28+x+%2B+y+%29%2A2.5+
-----------------------------------------
(2) +240+-+y+=+2.5x+%2B+2.5y+
(2) +2.5x+%2B+3.5y+=+240+
and
(1) +x+%2B+y+=+80+
(1) +2.5x+%2B+2.5y+=+200+
subtract (1) from (2)
+y+=+40+
and
(1) +x+%2B+40+=+80+
(1) +x+=+40+
--------------------------
They both travel at 40 km/hr
----------------------------------
check:
(2) +240+-+y+=+%28+x+%2B+y+%29%2A2.5+
(2) +240+-+40+=+%28+40+%2B+40+%29%2A2.5+
(2) +200+=+80%2A2.5+
(2) +200+=+200+
OK