Results 1 to 5 of 5

Math Help - Uh..Probably easy questions for you people out there

  1. #1
    Newbie
    Joined
    Sep 2008
    Posts
    2

    Uh..Probably easy questions for you people out there

    QUESTION 1
    A man bought a laptop and a digital camera. He paid $2400 in all.If the digital camera cost 20% of the cost of the laptop,how much did he pay for the laptop?

    QUESTION 2
    In a collection of red,blue and yellow balls,there are 500 balls altogether.35% of the balls are red,25% of the balls are blue and the rest of the balls yellow.If 100 blue balls are added to the collection,how would the overall percentages of the different colored balls be changed?What are the new percentages?Round off your answers to 1 decimal place.

    MY ANSWER TO QUESTION 2

    35% OF RED BALLS = 35 500 = 175 red balls
    100
    25% OF BLUE BALLS= 25 500 = 125 blue balls
    100

    40% OF YELLOW BALLS = 40 500 = 200 yellow balls
    100

    125 blue balls + 100 = 225 blue balls

    175 100% = 29 1 %
    600 6

    225 100% = 37 1 %
    600 2

    200 100% = 33 1 %
    600 3

    OH MAN! MY ANSWER WAS A DRAG TO WRITE.......

    Is my answer correct?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,110
    Thanks
    2
    Quote Originally Posted by mathscat idiot View Post
    QUESTION 1
    A man bought a laptop and a digital camera. He paid $2400 in all.If the digital camera cost 20% of the cost of the laptop,how much did he pay for the laptop?
    It's probably easy for you, too. You are just confusing yourself. I see from your other problem workings that you are rather haphazard about it. Be more deliberate and organized. I'll do the whole thing for free since you very niclely showed your work on the other one.

    Rule #1 - Name Stuff!
    Question #1 - Name What?
    Answer #1 - What does it want? Name that.

    "how much did he pay for the laptop?"

    Perfect

    L = How much he paid for the laptop

    There is also a camera in there. Fine.

    C = How much he paid for the camera.

    Now translate...

    "He paid $2400 in all"

    Fine.

    L + C = $2400 <== Make sure you see how this was translated.

    "the digital camera cost 20% of the cost of the laptop"

    C = (20%)*L <== Make sure you see how this was translated.
    or
    C = L*(0.20) <== You should be able to do such conversion in your sleep.

    Now solve, oftentimes by simple substitution.

    L + C = $2400
    Substitute
    L + (L*(0.20)) = $2400
    Combine like terms
    L(1.20) = $2400
    Divide
    L = $2400/1.20
    L = $2000

    C = L*(0.20) = ($2000)*0.20 = $400

    Check

    L + C = $2400
    Substitute
    $2000 + $400 = $2400 -- Perfect

    One more thing. Go REread the question and make sure we answered everthing it wanted. If we answered a little more than it asked, that might be fine. You would want to avoid that on a timed examination, but here it is good practice.

    Notice how organized this is. Thoughts go down on the paper. Do NOT try to do it all in your head. Do NOT skip steps. Do NOT give in to the temptation to avoid writing each step and each thought. Let the notation help you.

    Show us another one with some process improvements.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Sep 2008
    Posts
    2
    By the way,you got QUESTION 2 WRONG.

    HERE'S MY ANSWER

    Cost of laptop= 80 over 100 X $2400 = $1,920

    And by the way,the digital camera is $480,not $400!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by mathscat idiot View Post
    By the way,you got QUESTION 2 WRONG.

    HERE'S MY ANSWER

    Cost of laptop= 80 over 100 X $2400 = $1,920

    And by the way,the digital camera is $480,not $400!
    And by the way, your post is insulting and has been reported to the moderators. By the way.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by mathscat idiot View Post
    By the way,you got QUESTION 2 WRONG.

    HERE'S MY ANSWER

    Cost of laptop= 80 over 100 X $2400 = $1,920

    And by the way,the digital camera is $480,not $400!
    \frac{480}{1920}=0.25, or 25\%

    So this is wrong because the camera cost 20% or the cost of the laptop, not 20% of the total cost of the camera and laptop.

    So lets see TKH is correct and you are wrong, unless you asked the wrong question.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. two easy questions
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: August 29th 2011, 05:12 PM
  2. Replies: 1
    Last Post: February 14th 2011, 07:18 AM
  3. Replies: 3
    Last Post: March 28th 2009, 06:27 PM
  4. some Easy Questions
    Posted in the Algebra Forum
    Replies: 44
    Last Post: November 23rd 2008, 04:15 AM

Search Tags


/mathhelpforum @mathhelpforum