We can simply observe that.
- 0.777... is rational, because it is a number with infinite but repeating decimal part.
- 1/3 is rational, because it's the division between two integers
, so this is rational as well.
Since the product of two rational numbers is always rational, we have that

are all rationals, since they are the product of two rationals.
On the other hand, we have

and thus

which is irrational.
One may note, you never quite asked anything per se, ahemm, if you meant simplification.
320 guests / 5 servings per can = 64 cans required
Basically the answer is 6, if you'd like an explanation, let me know. :)
Answer:
By thinking logically,here's hint: there are only 4 equal sections and 4 colors,all of them equal to=

no matter what color you take,for example green is 1/4,red is 1/4 as well.Eventually the answer is:the probability of orange color is 1/4 too.