First, find how full the tank is:
3/8 x 25 or 0.375 x 25
= 9.375 gallons
Then, find the difference:
25 - 9.375
= 15.625
Also, find how much the 0.625 is worth.
1 - .625 = 0.375
.375 x 2.96
= $1.11
Now, all you have to worry about is the 15 gallons:
15 x 2.96
= $44.40
Add up to get the total:
44.4 + 1.11
=45.51
Your total is:
$45.51 to fill up your gas tank when it's already 3/8 full!
