Question 999333: Alan and Allie leave from the same point driving in opposite directions. Alan is driving at 55 mph and Allie at 65 mph. Alan has a one hour head start. How long will they be able to talk on their cell phones if the phones have a 250 mile range?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! distance = velocity * time
Alan is 55t, where t=hours
Allie is 65(t-1), since she started an hour later.
They add to 250 miles
mph/hr=miles (units)
55t+65t-65=250
120t=315
t=2.625 hours for A. (144.375 miles)
T=1.625 hours for All.(105.625 miles)
miles add to 250.
They can talk for 2.625 hours, assuming time is started when Alan leaves. Once they are both driving, they can talk for 1.625 hours. The question is ambiguous there.
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