Answer:
The probability of selecting a person which is self-employed but not married equals 1/8.
Step-by-step explanation:
Here, the given survey says:
Total number of people surveyed = 248
Number of people married = 156
The number of people are self employed = 70
Now, 25% of people who are married are SELF EMPLOYED.
Now, calculating 25% of 156 , we get:

⇒ out of total 156 married people, 39 are self employed.
So, number of self employed people but not married
= Self employed people - Self employed people PLUS married
= 70 - 39 = 31.
So, the probability that the person selected will be self-employed but not married =
= 
Hence The probability of selecting a person which is self-employed but not married equals 1/8.