I am pretty sure the awnser is yes because 2.5 divided by 3 equals .83 repeating which mean for one dozen of cupcakes(12) it would take .84 cups of flour.
The total number of alphabets are 26.
The total number of vowels are 5.
Th repetition is allowed.
The possible outocme for all to be vowels are,


The total outcome is,

Therefore, the probability that all 4 will be vowels ,


The probability is 0.137 %.