A seafood restaurant owner orders perch and salmon. Perch is four dollars per pound and salmon is three dollars per pound. He wants to buy at least 50 pounds of fish but cannot spend more than $240

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.