SOLUTION: Two cyclists, 90 km apart, start riding toward each other at the same time. The speed of one cyclist is twice as fast as the other. Find their speeds if they meet after 2 hours. (u

Algebra ->  Finance -> SOLUTION: Two cyclists, 90 km apart, start riding toward each other at the same time. The speed of one cyclist is twice as fast as the other. Find their speeds if they meet after 2 hours. (u      Log On


   

Question 1101062: Two cyclists, 90 km apart, start riding toward each other at the same time. The speed of one cyclist is twice as fast as the other. Find their speeds if they meet after 2 hours. (use algebra)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Think of this as one of them standing still
and the other one moving at the sum of their speeds
Let +s+ = the speed of the slower cyclist
+2s+ = the speed of the faster cyclist
-----------------------------------------
+90+=+%28+s+%2B+2s+%29%2A2+
+90+=+3s%2A2+
+90+=+6s+
+s+=+15+
and
+2s+=+30+
----------------
Their speeds are 15 km/hr and
30 km/hr
-----------------------------
check:
+d%5B1%5D+=+15%2A2+
+d%5B1%5D+=+30+ km
and
+d%5B2%5D+=+30%2A2+
+d%5B2%5D+=+60+ km
--------------------
+d%5B1%5D+%2B+d%5B2%5D+=+30+%2B+60+
+d%5B1%5D+%2B+d%5B2%5D+=+90+ km
OK