How many times should I fold a piece of paper, in order to exceed the distance between the earth and the moon?
Paper thickness: 0.07mm
Distance from Earth to the moon: 384,400 km
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Each folding of the paper doubles the thickness of the paper. That is, if we fold the paper n times, the paper's thickness is 2 n times its original thickness. As a result, 7 × 1 0 − 5 × 2 n = 3 . 8 4 4 × 1 0 8 2 n = 7 × 1 0 − 5 3 . 8 4 4 × 1 0 8 = 5 . 4 9 1 × 1 0 1 2 n = lo g 2 ( 5 . 4 9 1 × 1 0 1 2 ) = 4 2 . 3 2 Therefore, the answer is 4 3 , because 42 folds still falls short so we need an extra fold.
Thanks for sharing an explanation way better than mine!
Problem Loading...
Note Loading...
Set Loading...
First fold: 0.00000014
Second fold: 0.00000028
....
Forty second fold: 307,863
Forty third fold: 615,726
So we do on the calculator: Ans = Ans * 2 (starting with 0.00000007 km) counting the number of operations we make a long the way. When Ans reaches >384,400 we stop counting.
Therefore, the number of operations needed to exceed 384,400 is 43 .