SOLUTION: Jane leaves her house and drives in a straight line at a speed of 60 mph. Her speed on the return trip is 70 mph. The trip back home takes 15 minutes less than the outbound trip. W

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: Jane leaves her house and drives in a straight line at a speed of 60 mph. Her speed on the return trip is 70 mph. The trip back home takes 15 minutes less than the outbound trip. W      Log On

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Question 906491: Jane leaves her house and drives in a straight line at a speed of 60 mph. Her speed on the return trip is 70 mph. The trip back home takes 15 minutes less than the outbound trip. What was Jane's total travel time in hours? Assume both trips are in a straight line. Give your final answer as a simplified fraction.

I keep getting 1.75, or 1 3/4 but it is saying it is wrong. PLEASE HELP ASAP

Found 2 solutions by richwmiller, MathLover1:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
They want TOTAL trip not one way.
60*t=70*(t+-15/60)
60*t=70*t+-1050/60
60*t=70*t+-1050/60
1050/60=70+60*t
1050/60=10*t
1.75=t
t=1.75 hours one way
1.50+*1.75=3.25 or 3 1/4 hours for the trip
distance =60*1.75=105.0 miles
distance =70*1.5=105.0 miles

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

Jane leaves her house
d=60+mph%2At.....eq.1
the return trip, same distance
d=70+mph%2A%28t-15min%29 .....eq.1....15min=%2815%2F60%29+h=0.25h
d=70+mph%2A%28t-0.25h%29
since distance is same, we have
60+mph%2At=70+mph%2A%28t-0.25h%29 ....solve for t
60+mph%2At=70+mph%2At-70mph%2A0.25h
60+%28mil%2Fh%29%2At-70%28+mil%2Fh%29%2At=-70%28mil%2Fh%29%2A0.25h
%2860+%28mil%2Fh%29-70+%28mil%2Fh%29%29t=-17.5mil
-10%28mil%2Fh%29t=-17.5mil
t=-17.5mil%2F-10+%28mil%2Fh%29
t=1.75h...............time when Jane leaves her house
%28t-0.25h%29=%281.75h-0.25h%29=1.50h.. travel time back
total travel time in hours:
1.75h%2B1.50h=3.25h or 3 1/4 hours