Acomputer is used to pick three letters, one after the other, from {a. b}. each letter can be picked more than once and has the same chance of being selected. the possible outcomes for this experiment are shown in the table. aaa aab aba baa bba abb bab bbb drag and drop to match the value to the probability statement.

This is material out of the lesson of basic mathematics of compound probability. 

To solve this problem, we first must count the number of outcomes (n) for this experiment. There are 2 rows of 4, so there are 8 outcomes. Now we must find what exactly the answer is looking for.

The answer is looking for the answer to the compound probability statement; P( A then B then A). If you look at the table of outcomes (results), there is one result that matches ABA. So, find the number of specific outcomes from the set of events and divide it by the total number of outcomes. 

Solution:
1/8= 0.125

3x+9+4x+x=8x+9that's the answer for your question.

With a continuous thought process.