A gas station sells three types of gas Regular for 300 a gal

A gas station sells three types of gas: Regular for $3.00 a gallon, Performance Plus for $3.20 a gallon, and Premium for $3.30 a gallon. On a particular day 6500 gallons of gas were sold for a total of $20,050. Three times as many gallons of Regular as Premium gas were sold. How many gallons of each type of gas were sold that day?

Solution

Let regular gallon be x

per plus be y gallon

Premium be z gallons

On a particular day 6500 gallons of gas were sold

So, x+y+z = 6500 ------(1)

sold for a total of $20,050

3x + 3.2y + 3.3z = 20050 -----(2)

Three times as many gallons of Regular as Premium gas were sold

z = 3y ------(3)

Solve the abov equations

we get Regular = 4500 gallons

Per Plus = 500 gallons

Premium = 1500 gallons