Results 1 to 13 of 13
Like Tree3Thanks
  • 1 Post By MarkFL
  • 1 Post By MarkFL
  • 1 Post By Prove It

Math Help - the price of an item

  1. #1
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    the price of an item

    The price of a certain item was $10 in 1990 and it has gone up by $2 per year since 1990. If this trend continues, in what year will the price be $100?

    OA later
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    Re: the price of an item

    A large solid cube is assembled by gluing together identical unpainted small cubic blocks. All six faces of the large cube are then painted red. If exactly 27 of the small cubic blocks that make up the large cube have no paint on them, how many small cubic blocks make up the large cube?

    OA later
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    1,988
    Thanks
    734

    Re: the price of an item

    How long will it take the price to increase by $90 if it increases $2 per year?
    Thanks from agentmulder
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    Re: the price of an item

    yes.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    Re: the price of an item

    the OA is 2035. my answer is coming out to be 2036 by using the sum of arithmetic formula, where a=10, d=2, and l=100. n comes out to be 46.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    1,988
    Thanks
    734

    Re: the price of an item

    You don't want to use the summation formula if you are going to use the arithmetic progression approach, you want to use the formula for the nth term:

    a_n=a_1+(n-1)d

    With a_n=100,\,a_1=10,\,d=2 we find:

    100=10+2(n-1)

    90=2(n-1)

    n-1=45

    You see, we want the value of n - 1, not n, as year zero is 1990, not year 1.
    Thanks from agentmulder
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    Re: the price of an item

    Ok, thanks. And any help with the cube one?
    Follow Math Help Forum on Facebook and Google+

  8. #8
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    1,988
    Thanks
    734

    Re: the price of an item

    Quote Originally Posted by usre123 View Post
    Ok, thanks. And any help with the cube one?
    What is size of the interior cube with no paint?
    Follow Math Help Forum on Facebook and Google+

  9. #9
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,513
    Thanks
    1404

    Re: the price of an item

    Please only post one question per thread.
    Thanks from MarkFL
    Follow Math Help Forum on Facebook and Google+

  10. #10
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    1,988
    Thanks
    734

    Re: the price of an item

    Quote Originally Posted by Prove It View Post
    Please only post one question per thread.
    Yes, this is a very valuable suggestion...follow-up questions are fine within the same topic, but when you tag an unrelated question to an existing topic, it can make a topic convoluted and hard to follow.
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Newbie
    Joined
    Apr 2013
    From
    America
    Posts
    20

    Re: the price of an item

    ok I'm sorry. Should I move it to a new thread?

    I think volume of inner cube is 3, since 3*3*3 = 27. But I dont know where to go from there.
    Follow Math Help Forum on Facebook and Google+

  12. #12
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    1,988
    Thanks
    734

    Re: the price of an item

    Quote Originally Posted by usre123 View Post
    ok I'm sorry. Should I move it to a new thread?

    I think volume of inner cube is 3, since 3*3*3 = 27. But I dont know where to go from there.
    I think just keeping this in mind for the future is fine.

    What must the size of the outer cube be?
    Follow Math Help Forum on Facebook and Google+

  13. #13
    Super Member
    Joined
    Jul 2012
    From
    INDIA
    Posts
    828
    Thanks
    209

    Re: the price of an item

    if 27 cubes have no face painted then have the next bigger cube made be gluing small cubes on each face to complete the cube. Since the bigger cube is made of smaller cubes it should have 64 small cubes. Because 3 cube is 27 and 4 cube is 64. Now you can proceed further
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. 2nd-price sealed-bid auction with reserve price
    Posted in the Statistics Forum
    Replies: 0
    Last Post: November 27th 2012, 11:44 PM
  2. Item distribution
    Posted in the Statistics Forum
    Replies: 0
    Last Post: March 27th 2012, 12:11 AM
  3. Replies: 0
    Last Post: August 12th 2011, 05:09 PM
  4. Maximize price of Item
    Posted in the Business Math Forum
    Replies: 1
    Last Post: March 17th 2011, 08:39 PM
  5. box item problem
    Posted in the Statistics Forum
    Replies: 2
    Last Post: May 17th 2010, 05:01 PM

Search Tags


/mathhelpforum @mathhelpforum