SOLUTION: Alex plans to drive 550 miles from New York to Virginia, driving an average of 50 miles per hour. How many miles per hour faster must he average, while driving, to reduce his total

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Question 1083743: Alex plans to drive 550 miles from New York to Virginia, driving an average of 50 miles per hour. How many miles per hour faster must he average, while driving, to reduce his total driving time by 1 hour?
Found 3 solutions by Alan3354, rothauserc, addingup:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Alex plans to drive 550 miles from New York to Virginia, driving an average of 50 miles per hour. How many miles per hour faster must he average, while driving, to reduce his total driving time by 1 hour?
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Find the time at 50 mi/hr
--
d = r*t
t = d/r
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Then find the speed to take 1 hour less.
d = r*t
r = d/t

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
use rate * time = distance
:
time = 550 / 50 = 11 hours
:
Alex wants to reuce his travel time by 1 hour = 11 - 1 = 10 hours
:
rate = 550 / 10 = 55 mph
:
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Alex needs to average 55 - 50 = 5 mph faster than the 50 mph
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Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
550/50 = 11 hours
11-1 = 10 so he needs to do it in 10 hours:
550/10 = 55
New speed - Current speed: 55-50 = 5 mph faster