SOLUTION: Earth is covered by land and water. The proportion covered by land is 3/5 of that covered by water. What fraction of entire surface of earth is land ? Option are: 1/2, 3/8, 1/3, 2

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Earth is covered by land and water. The proportion covered by land is 3/5 of that covered by water. What fraction of entire surface of earth is land ? Option are: 1/2, 3/8, 1/3, 2      Log On


   

Question 779625: Earth is covered by land and water. The proportion covered by land is 3/5 of that covered by water. What fraction of entire surface of earth is land ?
Option are: 1/2, 3/8, 1/3, 2/5
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
L = Land
W = Water
L%2BW=1;
L=%283%2F5%29W.

The second equation rearranges to... not needed yet.
Substitute the second equation into the first equation and solve for W.
%283%2F5%29W%2BW=1
W%283%2F5%2B1%29=1
W%288%2F5%29=1
highlight%28W=5%2F8%29, requiring that highlight%28L=3%2F8%29