Doug, a student in this class, knows how to write programs in JAVA. Everyone who knows how to write programs in JAVA can get a high-paying job. Therefore, someone in this class can get high-paying job.

Missing Part of Question

Explain which rules of inference are used in the above

Universal instantiation, Modus ponens and Existential generalization

Step-by-step explanation:

Splitting the Statement into two, we have

"Doug knows how to write program is Java"

and

"Doug can get a high paying job"

Represent Doug with x. Then the statements is rewritten as

P(x) = "x knows how to write program is Java"

and

Q(x) = "x can get a high paying job"

In logic, A premise is a statement in an argument that provides reason or support for the conclusion.

So, Statement 1 can be written as

1. P(x) Premise

Then, we have

2. Vx(P(x) --> Q(x)) -- Premise. This mean that P(x) for all values in the domain.

The universal instantiation of (2) leads to

3. P(Doug) --> Q(Doug)

The modus ponens of the above gives

4. Q(Doug)

The existential generalisation from above gives

5. ƎxQ(x)

Which means someone in this class can get a high paying job.

PS:

Universal Instantiation is a valid rule of inference from a truth about each member of a class of individuals to the truth about a particular individual of that class; it is represented by VxP(x).

Existential Generalisation is a valid rule of inference that allows one to move from a specific statement, or one instance, to a quantified generalized statement, or existential proposition.

It is represented as ƎxP(x)

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.