Tom Quig traveled 280 miles east of St. Louis. For most of the trip he averaged 60 mph, but for one period of time he was slowed to 10 mph due to a major accident. If the total time of travel was 8 hours, how many miles did he drive at the reduced speed?
.
You will need to apply the "distance formula":
d = rt
where
d is distance
r is rate or speed
t is time
.
Let x = time driving at reduced speed
then
8-x = time driving at 60 mph
.
60(8-x) + 10x = 280
480 - 60x + 10x = 280
480 - 50x = 280
480 = 50x + 280
200 = 50x
4 hours = x
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This means he spent 4 hours driving at 10 mph, the distance he drove at this rate then is:
