Acompany is testing tires for wear and tear. a given tire is said to either pass the test (p) or fail the test (f). enter the missing outcome possibilities in each box to show the possible results if three tires are tested.
{ppp,( ), pfp, fpp, ffp, fpf,( )fff}

  PPF, PFF

Step-by-step explanation:

There are several ways you can list all the possible combinations. A couple of my favorite are a) use a binary counting sequence; b) use a gray code counting sequence.

Using the first method, the binary numbers 000 to 111 can be listed in numerical order as 000, 001, 010, 011, 100, 101, 110, 111. Letting 0=P and 1=F, the ones missing from your list are the ones in italics in my list.

Using the second method, we change the right-most character, then the middle one, and finally the left-most character so there is one change at a time: 000, 001, 011, 010, 110, 111, 101, 100.

After you have a list of all possible combinations, it is a simple matter to compare the given list to the list of possibilities to see which are missing.

the solution is 12x-6y