B varies directly as c and inversely as d. One set of values is b = 5.75, c = 2.3, and d = 0.3.
Find b when c = 0.5 and d = 0.15.

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.