Final answer:
To find the number of gallons Richard Brian purchased, divide the total price by the price per gallon.
Step-by-step explanation:
To find the number of gallons Richard Brian purchased, we can use the formula:
number of gallons = total price / price per gallon
In this case, Richard Brian put $30 worth of gas in his truck and the price per gallon was $2.50. So, the equation to solve for the number of gallons is:
number of gallons = $30 / $2.50
Dividing $30 by $2.50, we get:
number of gallons = 12
Therefore, Richard Brian purchased 12 gallons of gas.