SOLUTION: Two planes, which are 2920 miles apart, fly toward each other. Their speeds differ by 80 mph. If they pass each other in 4 hours, what is the speed of each?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Two planes, which are 2920 miles apart, fly toward each other. Their speeds differ by 80 mph. If they pass each other in 4 hours, what is the speed of each?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1069037: Two planes, which are 2920 miles apart, fly toward each other. Their speeds differ by 80 mph. If they pass each other in 4 hours, what is the speed of each?
Found 2 solutions by josmiceli, josgarithmetic:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
In this type of problem, you can think of one of
the planes as standing still, and the other one
flying at the sum of their speeds
-------------------------------
Let +s+ = the speed in mi/hr of the slower plane
+2920+=+%28+s+%2B+s+%2B+80+%29%2A4+
+2920+=+%28+2s+%2B+80+%29%2A4+
+2920+=+8s+%2B+320+
+8s+=+2920+-+320+
+8s+=+2600+
+s+=+325+
and
+s+%2B+80+=+405+
--------------------
Their speeds are
325 mi/hr and 405 mi/hr
-----------------------------
check:
+d%5B1%5D+=+325%2A4+
+d%5B1%5D+=+1300+ mi
and
+d%5B2%5D+=+405%2A4+
+d%5B2%5D+=+1620+
and
+d%5B1%5D+%2B+d%5B2%5D+=+1300+%2B+1620+
+d%5B1%5D+%2B+d%5B2%5D++=+2920+
OK

Answer by josgarithmetic(39621) About Me  (Show Source):