Question 58603: At 10Am, adam started out at 60 kilometers per hour to catch tom , who had a three hour head start. If adam was still 70 kilometers behind at 6 pm, how fast was tom driving?
Found 2 solutions by Edwin McCravy, stanbon:
Answer by Edwin McCravy(20056)   (Show Source):
You can put this solution on YOUR website! At 10Am, adam started out at 60 kilometers per hour to catch tom , who had a
three hour head start. If adam was still 70 kilometers behind at 6 pm, how fast
was tom driving?
Make this chart
DISTANCE RATE TIME
Adam
Tom
Let Tom's rate be x. Fill this in and
also Adam's rate, which is 60.
DISTANCE RATE TIME
Adam 60
Tom x
At 6 pm, Adam had driven since 10AM,
which is 8 hours. Tom has a three hour
head start, so at 6 PM Tom had driven
for 11 hours. So fill in Adam's and
Tom's times:
DISTANCE RATE TIME
Adam 60 8
Tom x 11
Use DISTANCE = RATE × TIME to fill in
the distances:
DISTANCE RATE TIME
Adam 480 60 8
Tom 11x x 11
Since Adam was 70 km behind Tom at
6 PM, then
Adam's distance = Tom's distance minus 70
480 = 11x - 70
Solve that and you'll get that Tom's rate
is 50 km/h
Edwin
Answer by stanbon(75887)  (Show Source):
You can put this solution on YOUR website! At 10Am, adam started out at 60 kilometers per hour to catch tom , who had a three hour head start. If adam was still 70 kilometers behind at 6 pm, how fast was tom driving?
--------------
Adam DATA:
rate= 60 km/hr ; time = 8 hr. ; distance = tr= 480 km
---------
Tom DATA:
time=8+3 = 11 hr;
Let Tom's rate be x km/hr
In 3 hrs he goes 3x km
He then covers the 480 km that Adam covers later
He then is 70 km ahead of Adam
Tom's distance = 3x+480+70=3x+550 km
Tom's distance is also 11x because he was on the road for 11 hours
EQUATION:
3x+550=11x
8x=550
x=68.75 km/hr (This is Tom's rate)
Cheers,
Stan H.
rate=d/t=550/11=50 km/hr
-----------------
Tom's rate is 50 km/hr.
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