math...?

posted by .

to save fuel on the 240 km trip to the cottage, the Nakamura family reduce their usual average speed by 20 km/h. this lengthens their journey by 1 hour. what is the slower average speed?


i was told this question is not complete to answer? is that true?

  • math...? -

    normal speed ---- x km/h
    time at normal speed = 240/x hours

    reduced speed --- x-20 km/h
    time at reduced speed = 240/(x-20)

    solve:
    240/(x-20) - 240/x =1

    hint: multiply each term by x(x-2)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. College Algebra

    A truck driver traveled at an average speed of 55 miles per hour on a 200 mile trip to pick up a load of freight. On the return trip(with the truck fully loaded), the average speed was 40miles per hour. What was the average speed for …
  2. math

    a truck driver traveled at an average speed of 48 miles per hour on a 100-mile trip to pick up a load of freight. On the return trip with the truck fully loaded,the average speed was 40 miles per hour. Find the average speed for the …
  3. MATH

    Hello! I am trying to finish a math assignment. it was a bunch of math questions, and I am having a very difficult time with 5 of them. I have the answers to them though. Could somebody please help me with AT LEAST a few!?
  4. MATH

    Hello! I am trying to finish a math assignment. it was a bunch of math questions, and I am having a very difficult time with 5 of them. I have the answers to them though. Could somebody please help me with AT LEAST a few!?
  5. math

    to save fuel on the 240 km trip to the cottage, the Nakamura family reduce their usual average speed by 20 km/h. this lengthens their journey by 1 hour. what is the slower average speed?
  6. Math

    A motorist makes a journey of 240 km from Singapore to Malacca to visit his inlaws at an average speed of x kilometers. On his return journey, his average speed is reduced by 6km/hour due to traffic. If the return journey takes 20 …
  7. Pre Calc

    A bus trip of 90 miles would have taken an hour less if the usual average speed had been increased by 3 miles per hour. Find the usual average speed of the bus.
  8. Physics

    Help I don't understand how to do this homework question, we didn't go over any like it in class. A car has an average speed of 80.0km/h for 1 hour, then an average speed of 90.0km/h for 2 hours during a 3 hour trip. what was the average …
  9. Math

    On a trip of d miles to another city, a truck driver's average speed was x miles per hour. On the return trip the average speed was y miles per hour. The average speed for the round trip was 50 miles per hour. Show that y=25x/(x-25) …
  10. Math Algebra

    A drive took some hours to travel from Rome to Milan. His average speed for the whole journey was 80 km/hour. For the first half of the journey he traveled at an average speed of 50km/hour. Find his average speed for the second half …

More Similar Questions