Answer: $47.60
Step-by-step explanation: First, we will multiply $2.08 by 20 because we want to know how much it will cost for 20 gallons of gas.
$2.08 x 20 = $41.60
Now, just add the $6.00 car wash to the total amount of gas which is $41.60.
$41.60 + $6.00 = $47.60
So, the total amount of his purchase was $47.60