Three tenths of our planet Earth is covered with land and the rest is covered with water. Ninety-seven percent of the water is salt water and the rest is fresh water. What percentage of the Earth is covered in fresh water?
(A) $20.1 \%$
(B) $79.9 \%$
(C) $32.1 \%$
(D) $2.1 \%$
(E) $9.6 \%$
Three tenths of our planet Earth is covered with land and the rest is covered with water. Ninety-seven percent of the water is salt water and the rest is fresh water. What percentage of the Earth is covered in fresh water?
(A) $20.1 \%$
(B) $79.9 \%$
(C) $32.1 \%$
(D) $2.1 \%$
(E) $9.6 \%$

## Solution

If three tenths of Earth is covered with land then seven tenths or 70\% is covered with water. If $97 \%$ of this water is salt water then just $3 \%$ is fresh water. This implies that $3 \%$ of $70 \%$ or $(0.03)(0.7)=0.021=2.1 \%$ of the Earth is covered in fresh water.

ANSwER: (D)