SOLUTION: At 8am John leaves his home on a trip driving 40mph. 15 minutes later Jane discovers that he had forgotten his papers. She drives 60mph to catch up with him. She is delayed 30 m

Algebra ->  Average -> SOLUTION: At 8am John leaves his home on a trip driving 40mph. 15 minutes later Jane discovers that he had forgotten his papers. She drives 60mph to catch up with him. She is delayed 30 m      Log On


   

Question 32523: At 8am John leaves his home on a trip driving 40mph. 15 minutes later Jane discovers that he had forgotten his papers. She drives 60mph to catch up with him. She is delayed 30 minutes. When will she catch up with John? I have had one like this before and cannot remember how it is worked, the 30 min delay and the 15 minutes later have me all messsed up. Help please.
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Le the time be x:
She is delayed 30 minutes is probaly the hardest part of this eqaution:
Delyaed 30 minutes from original time gives us:
x-0.5 because 30 minutes = 0.5hours.
15 minutes later means x+0.25. 15 minutes is 0.25 hours.
Eqaution:
40(x+0.25)=60(x-0.5)
40x+10=60x-30
-20x=-40
x=2
2-0.5=1.5
Hence, it will take her 1.5 hours to catch up with John.
Paul.