Acafe sells puffs. 5/9 are beef and 1/3 are chicken. the remaining 18 are tuna. calculate 1. what fraction of the puffs are tuna and 2. how many puffs are there in all. i really need to see the working for this.

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:

5/9 + 1/3 + tuna = 1

tuna =   1  - 5/9 - 1/3.           LCM = 9

tuna = 9/9 - 5/9 - 3/9 = (9 - 5 - 3)/9 = 1/9

Fraction of tuna = 1/9

Let all the puffs be x.   Recall there are 18 tuna

(1/9)x = 18

x/9 = 18

x = 9*18

x = 162

There are 162 puffs in all.

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