The volume of one of the great lakes is 3.5 × 103 cubic kilometers. if there are 6.3 × 107 fish in the lake, what is the average number of fish per cubic kilometer?

The answer is 1.8 x 10^4, which is B

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.