SOLUTION: Mark drove to visit his grandma at 75km/hr. He returned at 50km/hr. It took 45 minutes longer to return home than to get to his grandmas house, how long dod it take him to get home

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Question 897700: Mark drove to visit his grandma at 75km/hr. He returned at 50km/hr. It took 45 minutes longer to return home than to get to his grandmas house, how long dod it take him to get home?
Found 2 solutions by lwsshak3, stanbon:
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Mark drove to visit his grandma at 75km/hr. He returned at 50km/hr. It took 45 minutes longer to return home than to get to his grandmas house, how long dod it take him to get home?
***
let x=travel time to grandma's house
x+45min=travel time to return home
distance=speed*travel time
..
45 min=45/60 hr=3/4 hr
75x=50(x+3/4)
75x=50x+37.5
25x=37.5
x=1.5
x+3/4=2.25
how long did it take him to get home? 2.25 hr

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Mark drove to visit his grandma at 75km/hr. He returned at 50km/hr. It took 45 minutes longer to return home than to get to his grandmas house, how long dod it take him to get home?
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To Grandma DATA:
rate = 75 km/hr ; distance = x km ; time = d/r = x/75 hrs
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From Grandma DATA:
rate = 50 km/hr ; distance = x km ; time = d/r = x/50 hrs
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Equation:
time - time = 3/4 hr
x/50 - x/75 = 3/4
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Multiply thru by 300 to get:
6x - 4x = 36
2x = 36
x = 18 km (distance)
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Cheers,
Stan H.
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