Results 1 to 7 of 7

Math Help - area

  1. #1
    Junior Member
    Joined
    Dec 2007
    Posts
    64

    area

    hello everybody
    The area of 5% of an island is 3km squared. What is the area of the whole island? Thank you.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    GAMMA Mathematics
    colby2152's Avatar
    Joined
    Nov 2007
    From
    Alexandria, VA
    Posts
    1,172
    Awards
    1
    Quote Originally Posted by Sweeties View Post
    hello everybody
    The area of 5% of an island is 3km squared. What is the area of the whole island? Thank you.
    Well, let A be the area of the island.

    .05A = 3
    A = \frac{3}{.05} \Rightarrow 3*20 = 60
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jan 2008
    Posts
    76
    Think of 5% as a fraction. 5% is the same as saying \frac{1}{20}. What do you get when you consider 3km is \frac{1}{20} of a larger number?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor kalagota's Avatar
    Joined
    Oct 2007
    From
    Taguig City, Philippines
    Posts
    1,026
    Quote Originally Posted by Sweeties View Post
    hello everybody
    The area of 5% of an island is 3km squared. What is the area of the whole island? Thank you.
    if x is the total area of the island? how do you represent the 3km?
    ans: 5% of x = 3km
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Dec 2007
    Posts
    64
    Quote Originally Posted by XIII13Thirteen View Post
    Think of 5% as a fraction. 5% is the same as saying \frac{1}{20}. What do you get when you consider 3km is \frac{1}{20} of a larger number?
    I got the answer using colby2152 's method. But how would you do it using this one? I couldn't get it.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    GAMMA Mathematics
    colby2152's Avatar
    Joined
    Nov 2007
    From
    Alexandria, VA
    Posts
    1,172
    Awards
    1
    Quote Originally Posted by Sweeties View Post
    I got the answer using colby2152 's method. But how would you do it using this one? I couldn't get it.
    3=\frac{1}{20}A

    3*20=A

    A=60
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Member
    Joined
    Jan 2008
    Posts
    76
    Sorry, I didn't want to create confusion. I thought I was putting it into a different context so you could look at it from a different perspective. Any of the listed methods will work, you should go with the one in which you are most comfortable. Colby gives a good example using either method.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. area-preserving maps between regions of equal area
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: August 23rd 2010, 09:33 PM
  2. Replies: 3
    Last Post: May 25th 2010, 01:01 AM
  3. Lateral Area and Total Surface Area
    Posted in the Geometry Forum
    Replies: 1
    Last Post: May 25th 2009, 05:28 PM
  4. Replies: 2
    Last Post: November 10th 2008, 10:27 AM
  5. Replies: 4
    Last Post: April 20th 2008, 08:03 PM

Search Tags


/mathhelpforum @mathhelpforum