Question

If about 1/40 of the earths water is fresh water. About 3/10 of the earths fresh water is ground water. What fraction of the earths water is ground water.

Answer 1

Answer:

3/400

Step-by-step explanation:

Let w represent earth's water

let f represent fresh water and let g represent ground water

$f = \frac{1}{40}w$

$g =\frac{3}{10}f = \frac{3}{10}(\frac{1}{40}w)\\ \\g = \frac{3}{400}w$

Therefore, fraction of earth's water,w, that is ground water = 3/400

Answer 2

Answer: Ground water is 3/400 of earth's water

Step-by-step explanation:

Let x represent earth's water,

F represent earth's fresh water, and

G represent earth's ground water.

The statement can then be expressed as follows:

About 1/40 of the earth's water is fresh water:

(1/40)x = F

About 3/10 of the earths fresh water is ground water:

Say: (3/10)F = G

=> (3/10)(1/40)x = G

(3/400)x = G

Therefore, ground water is 3/400 of the earth's water.