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Posted 11 May 2010 - 10:41 PM
I am new here and I may be all wrong, but when I worked this out I got 192 or double 96.
Here's my work:
Original width = 9
1st wish: 9 * 1/3 = 3
2nd wish: 3 * 1/3 = 1
3rd wish: 1 * 1/3 = 1/3
Current width is 1/3 cm. Total area must be 1/3 * L = 16 cm
L = 16 / 1/3 = 48
Current Length must be 48 cm.
Working backwards: 3rd wish = 48
2nd wish = 48 * 2 = 96
1st wish = 96 * 2 = 192 original length.
What did I miss?
you got the first bit right, the width after three wishes is 1/3cm, but then you said the area was 16cm. its meant to be 4cm^2, which is not the same as 16cm
so instead of 1/3 * L = 16cm, it should be
1/3 * L = 4 to find length after 3 wishes
i havent checked my answer, but looking at your post, that jumped out at me.
hope it helps
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