Puzzled ! Math Minded

[abl1111]

This has been a Thanksgiving brain tease for a few of my friends:

If I have 2.5 gallons of gas with 32 oz of 2 stroke oil in a container;

How much of the above mixture is needed to be mixed with fresh gas to make 1 gallon of a 50:1 ( fuel to oil ) mixture ?

I 'think' I figured it out, but a buddy is adamant about his different answer. All in the name of making use of my fogging mix for my i/o ! I wish I just threw it in my car and was done with it - but being a fix-it guy, it's bothering me !