A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing


  • 2 years ago

Driving along a crowded freeway, you notice that it takes a time t to go from one mile marker to the next. When you increase your speed by 5.0 mi/h, the time to go one mile decreases by 12 s. What was your original speed?

  • This Question is Open
  1. kropot72
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The original speed is 1/t mi/h. The increased speed is 1/t + 5 mi/h. The time to go one mile at the increased speed is given by: \[\large \frac{1}{\frac{1}{t}+5}\ .......(1)\] We can equate the time in (1) with the decreased time to go one mile as follows: \[\large \frac{1}{\frac{1}{t}+5}=t-\frac{12}{3600}\ .........(2)\] Manipulation of (2) produces the following quadratic equation: \[\large 1500t ^{2}-5t-1=0\ ...........(3)\] The real solution of (3) gives the original time to travel one mile as a decimal fraction of an hour. The reciprocal gives the original speed in mi/h.

  2. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...


  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.