A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Please Help this is killing me right now. I know how to solve this word problem once it is set up, but I just don't know how to set it up. The radiator of a car needs to contain 40 liters of 40% anti freeze. The radiator now contains 40 liters of 20% antifreeze. How many liters of this solution must be drained and replaced with 100% antifreeze to get the desired strength?

  • This Question is Closed
  1. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    amount(%) is the key to this stuff: x+y = 40; y = 40-x ................................... replace the y with its 'value' from above and solve for x x(.2) + y(1) = 40(.4)

  2. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    makes sense?

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so 30 liters? 30 liters must stay so 10 liters need to be drained?

  4. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    dunno; let me do the math :)

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay haha

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    This problem is haunting my life right now. It's the devil...

  7. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    .2x + 40 - x = 16 .2x - x = 16-40 -.8x = -24 x = 24/.8 = 240/8 = 30 there should be 30 liters of 20% so we need to drain 10 liters and top it with 100%

  8. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    lets check that :)

  9. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    30(.2) + 10(1) = 40(.4) 6 + 10 = 16 16 = 16....we are goood

  10. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    OMG! i did that, but for some reason i thought it was wrong.... lame thanks dude!

  11. amistre64
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    :) youre welcome

  12. Preetha
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    good work Amistre64. Nice set up of the equation.

  13. 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...

23

  • 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.