SOLUTION: A truck left Huck’s trucks and traveled north on 80 km/h. one hour later, anther truck left Huck’s trucks and traveled south at 60 km/h. how many hours had the first truck traveled

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Question 398817: A truck left Huck’s trucks and traveled north on 80 km/h. one hour later, anther truck left Huck’s trucks and traveled south at 60 km/h. how many hours had the first truck traveled when they were 150 km apart?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
when the 2nd truck left, the 1st truck
traveled d+=+80%2A1
d+=+80 km
Let t = time in hours after 2nd truck leaves
and they are 150 km apart
The second truck travels d%5B2%5D+=+60t
The 1st truck travels d%5B1%5D+=+80t
I have to add d+%2B+d%5B1%5D+%2B+d%5B2%5D+=+150 km
80+%2B+80t+%2B+60t+=+150
140t+=+70
t+=+.5 hrs
The 1st truck had traveled 1+%2B+.5 = 1.5 hrs
when they were 150 km apart
check answer:
d%5B1%5D+=+80t
d%5B1%5D+=+80%2A.5
d%5B1%5D+=+40
and
d%5B2%5D+=60t
d%5B2%5D+=+60%2A.5
d%5B2%5D+=+30
and
d+%2B+d%5B1%5D+%2B+d%5B2%5D+=+150
80+%2B+40+%2B+30+=+150
150+=+150
OK