SOLUTION: A man drives at a speed of 40 miles/hr. His wife left 30 mins. late with 50 miles/hr speed. when will they meet

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Question 495201: A man drives at a speed of 40 miles/hr. His wife left 30 mins. late with 50 miles/hr speed. when will they meet
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The man has a head start of:
+d+=+40%2A%281%2F2%29+
+d+=+20+ mi
------------
Start a stopwatch when the wife leaves
Let +d%5Bw%5D+ = her distance to when they meet
For man:
(1) +d%5Bw%5D+-+20+=+40t+
For wife:
(2) +d%5Bw%5D+=+50t+
-----------------
Substitute (2) into (1)
(1) +50t+-+20+=+40t+
(1) +10t+=+20+
+t+=+2+
They will meet in 2 hrs
check answer:
(1) +d%5Bw%5D+-+20+=+40t+
(1) +d%5Bw%5D+=+40%2A2+%2B+20+
(1) +d%5Bw%5D+=+100+
and
(2) +d%5Bw%5D+=+50t+
(2) +d%5Bw%5D+=+50%2A2+
(2) +d%5Bw%5D+=+100+
OK