Since the communative property shows you can add or multipy in any order, this means you can add all three of these in a different order and still get the same answer.....For example, you can do $1.25 + $0.80 + $2.75 or you can switch it around and do it in another way
Let n be the total number of puffs. Now we can write:

Adding the fractional value of n, we get:

Simplifying and rearranging gives us:

Therefore we can simplify to get:

and finally

The fraction of the puff that are tuna is found from:
If you take a moment and solve each equation (find the value
of the letter in each one), it'll jump out at you.
Here, let me do it for you. Why should you tire yourself.
5x = 20 . . . . . x = 4
4b = 7 . . . . . . b = 7/4
8w = 32 . . . . . w = 4
12y = 48 . . . . . y = 4
The second equation is not like the others.
It's the only one where the letter is not equal to 4 .