Question 441573
Tom Quig traveled 260 miles east of St Louis. For most of the trip he averaged 60mph. At one period of time he drived 20mph due to a major road accident. Total trip lasted 7 hours. How many miles did he traveled at reduced speed?
--------------------------------
Equations:
Let "s" be distance traveled at 60mph; Let "t" be dist. traveled at 20mph.
Distance Eq: s + t = 260 miles
---
Use distance/rate = time to get:
Time Eq::: s/60 + t/20 = 7 hrs
---------------------------------------
Rearrange:
s + t = 260 
s + 3t = 60*7
--------------------
Subtract and solve for "t":
2t = 160
t = 80 miles (distance traveled at 20 mph)
Solve for "s":
s + t = 260
s + 80 = 260
s = 180 miles (distance traveled at 60 mph)
==========================================
Cheers,
Stan H.