SOLUTION: Jerry drove for 4 hours before lunch. After lunch he drove 5 more hours and averaged 10 mph less than he did before lunch. If his total distance was 400 miles, then what was his av
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Question 953475: Jerry drove for 4 hours before lunch. After lunch he drove 5 more hours and averaged 10 mph less than he did before lunch. If his total distance was 400 miles, then what was his average speed before lunch? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = his average speed before lunch
Let = the distance in miles he drove before lunch
---------------
Before lunch:
(1)
After lunch:
(2)
----------------------------
Substitute (1) into (2)
(2)
(2)
(2)
----------------
His average speed before lunch was 50 mi/hr
check:
(1)
(1)
(1)
and
(2)
(2)
(2)
(2)
OK
