So since each pack has 6 packs we need to multiple. 6x8= 48.
There were 48 diet sodas in the cooler. 40 were drank. The fraction would be 40/48 were drank or 8/48 cans were not drunk.
For the lowest term, it would be 1/6 for 8/48 and 5/24 for 40/48.
Good luck with your studies! <3