SOLUTION: It took Teresa a total of 4 hours to drive 75 km to the airport and then fly 2100 km to Baguio City.If the plane rate is 12 times faster than her car,how fast did she drive?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: It took Teresa a total of 4 hours to drive 75 km to the airport and then fly 2100 km to Baguio City.If the plane rate is 12 times faster than her car,how fast did she drive?       Log On

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Question 376824: It took Teresa a total of 4 hours to drive 75 km to the airport and then fly 2100 km to Baguio City.If the plane rate is 12 times faster than her car,how fast did she drive?

Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
Distance(d) equals Rate(r) times Time(t) or d=rt; r=d/t and t=d/r
Let r=the speed (rate) that Teresa drove
Then 12r=speed of the plane
Time spent driving =75/r
Time spent flying=2100/12r=175/r
Now we are told that the above times add up to 4 hrs, sooooo:
75/r+175/r=4 multiply each term by r
75+175=4r
4r=250
r=62.5 km/hr----Teresa's driving speed
CK
It took Teresa 75/(62.5)=1.2 hrs to drive 75 km
It took plane 2100/(62.5*12)=2100/750=2.8 hr to fly to Baguio RP
1.2+2.8=4 hrs
Hope this helps---ptaylor