DISCRETE MATHEMATIC

Q1 - Q3 are word problems given as a sequence of hypotheses/
premises ending with "Therefore conclusion". Show that each
word problem is a valid argument.
Use rules of inference to show steps and reasons in the proof.

1) If I take a bus or subway then I'll be late for my
appointment.
If I take a taxi then I will be on time for my appointment and
I will be broke. If I don't take the subway and don't take a bus
then I will take a taxi. I will not be late for the appointment.
Therefore, I will be broke.

The conclusion "T" logically follows from the premises given and the argument is valid

Step-by-step explanation:

Let us use notations to represent the steps

P: I take a bus

Q: I take the subway

R: I will be late for my appointment

S: I take a taxi

T: I will be broke

The given statement in symbolic form can be written as,

(P V Q) → R

S → (¬R ∧ T)

(¬Q ∧ ¬P) → S

¬R

∴ T

PROOF:

1. (¬Q ∧ ¬P) → S                Premise

2. S → (¬R ∧ T)                  Premise

3. (¬Q ∧ ¬P) → (¬R ∧ T)    (1), (2), Chain Rule

4. ¬(P ∨ Q) → (¬R ∧ T)      (3), DeMorgan's law

5. (P ∨ Q) → R                   Premise

6. ¬R                                 Premise

7. ¬(P ∨ Q)                        (5), (6), Modus Tollen's rule

8. ¬R ∧ T                          (4), (7), Modus Ponen's rule

9. T                                   (8), Rule of Conjunction

Therefore the conclusion "T" logically follows from the given premises and the argument is valid.

the multiples of 15 are 15, 30,45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195,   210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 360, 375,   390, 405, 420, 435, 450, 465, 480, 495, 510, 525, 540, 555, 570, 585, 600, 615, 630, 645, 660, 675, 690, 705, 720, and 735.

the factors of 15 are 1, 3, 5, and 15.

hope that , fam!

-une, your fren : )