Questions on Logic: Proofs answered by real tutors!

Tutors Answer Your Questions about Proofs (FREE)

Question 242905: How do I solve these proofs?
Number one
1.~B v[(C>D)&(E>D)]
2. B&(C v E) /therefore, D

Number two
1. W&(A&M)
2. (A&W)>([(N v(R v H)]
3. ~N & (~P&~H) /therefore, R

Number three
1. (O&T)>(S&M)
2. R>~M
3. T&R
4. O&S /therefore, V

Number 4. last one
1. F>W /therefore, (F&S)>W

Click here to see answer by jim_thompson5910(35256)

Question 243039: may you please help me with solving:
1. O -> P
P -> ~P
________
|- ~O

Click here to see answer by jim_thompson5910(35256)

Question 243966: I need help solving this. I'm confused.
1. (RvS)>(T&U)
2. ~R>(V>~V)
3. ~T /Therefore ~V
Click here to see answer by jim_thompson5910(35256)

Question 244033: 1. F->(G.H)
2. H.G)->J ∴ F->J
Click here to see answer by jim_thompson5910(35256)

Question 246808: Given: Either south High won the championship or North High won the championship. If Larissa scored 50 points and Tamara was in the game , Kate was not not point guard. If Larissa did not score 50 points, North High did not win the championship. Kate was the point guard. Tamara was in the game.
Prove: South High won the championship
Click here to see answer by solver91311(24713)

Question 248098: I am working on proofs for my logic homework.
Here are the premises:
1. ~S -> (~G v ~F)
2. (~F -> ~W) & W
Here is the conclusion:
S v ~G
Click here to see answer by jim_thompson5910(35256)

Question 248111: Well I got most of my work done, but this one is stumping me. Logic Proofs.
Premises:
1. ~(P & F)
2. ((W v L) -> P) & W
3. L -> F
Conclusion:
~L
Click here to see answer by jim_thompson5910(35256)

Question 248179: This one is ridiculous, please help me with this proof.
Premises:
1. (~B v A) -> (C & D)
2. A -> ~C
3. ~A -> ~B
Conclusion:
~(B <-> C)
Click here to see answer by jim_thompson5910(35256)

Question 249373: Solve please.
1. ~S->(~Gv~F)
2. (~F->~W).W
:. Sv~G
Click here to see answer by jim_thompson5910(35256)

Question 249372: I need to solve this conditional proof and I can't. Help?
1. ~(M.~L)->Q
:. ~L->Q
Click here to see answer by jim_thompson5910(35256)

Question 250587: 1) Vv(F&G)
2) V->E
3) G->(M->I)
4) M // therefore, IvE
5) (G&M)->I 3 Exportation
6) -(G&M)vI 5 Material Implication
7) (VvF)&(VvG) 1 Distribution
- = negation
How do I figure out this proof?
Click here to see answer by jim_thompson5910(35256)

Question 250703: can you help me solve this proof using the first 13 rules of inference please?
1.Ev~(DvC)
2(Ev~D)->C
the desired answer is E.
Click here to see answer by jim_thompson5910(35256)

Question 251010: Just one premise, but a difficult conclusion
S -> T
We have to show (U v S) -> (U v T)
Click here to see answer by solver91311(24713)

Question 251757: What is the proof for
((P→Q)→Q)→(P∨Q)
Click here to see answer by drk(1908)

Question 251009: This stuff is crazy
O & I
O -> (S v G)
I -> ~G
We have to show S
Click here to see answer by drk(1908)

Question 251009: This stuff is crazy
O & I
O -> (S v G)
I -> ~G
We have to show S
Click here to see answer by jim_thompson5910(35256)

Question 252111: abc is a triangle with the vertices a,b and c. if a circle is drawn through a,b and c to circumscribe the triangle. line segments ab and ac are extended beyond points b and c respectively. a circle is drawn so that the extended line segments and the side BC are tangents to the circle.the same is repeated to the other two sides of triangle abc
the centers of the three circles e scribing triangle a,b,c are joined by line segments to form a triangle pqr.
show that the circle circumscribing pqr has twice the radius of the circle circumscribing ABC
what is the distance between the centers of the two circles if abc has the sides of length 12.15,and 17?
Click here to see answer by Edwin McCravy(20054)

Question 251006: Stumped
C <-> T
~C -> (~S v ~R)
~C -> D
(~D v S) & (~D v R)
We have to show T
Click here to see answer by Edwin McCravy(20054)

Question 251007: There is only one premise, and the conclusion has different letters
Here it is:
A -> B
We have to show (A & C) -> B
Click here to see answer by richwmiller(17219)

Question 251007: There is only one premise, and the conclusion has different letters
Here it is:
A -> B
We have to show (A & C) -> B
Click here to see answer by jim_thompson5910(35256)

Question 253094: what is the contrapositive of "If 3<4 then 3 is an odd number."
Click here to see answer by richwmiller(17219)

Question 251008: This one is nuts
A -> (D -> E)
F -> [(A & B) v (A & ~B)]
We have to show (F & D) -> E
Click here to see answer by solver91311(24713)

Question 255427: (R->B)&(B->~C),D <-> (P&~K),R&C |- M
I recently started taking an intensive Logic class and I am falling behind. Can you please help me solve this exercise so i can get an idea how to do these type of exercises? thanks so much
JT
Click here to see answer by jim_thompson5910(35256)

Question 259397: A student claims that the equation the !-x = 3 (square root of) has no solution, since the square root of a negative number does not exist. Why is this argument wrong? (The teacher do NOT want to solve this equation, she just wants to know why is the argument wrong)
Click here to see answer by richwmiller(17219)

Question 260233: Looking for a Proof to the theorem that given x>c, then 1/x < 1/c for any Real numbers x and c.
Thanks,
Gary
Click here to see answer by richwmiller(17219)

Question 260642: Hello,
Can someone please help me I have asked several question but I have not received any answer, if someone would please help me with the following.

a.r: The apartment is hot. q: The air conditioner is working. p: The temperature is 90.
Write the following in symbolic form

The temperature is not 90 and the air conditioner is working, but the apartment is hot.
COnstruct a truth table for the statement
~ (~ p<---> q)

Click here to see answer by jim_thompson5910(35256)

Question 261364: Hello

Someone told me to put this in the logic topic. So here it is again.Can someone please help me with the following I have been out of school to 20years

Translate the argument into sym-bolic form and ( b)
determine if the argument is valid or in-valid. You may
compare the argument to a standard form or use a truth
table.

If you pass general chemistry, then you can take organic
chemistry. You pass general chemistry.
_____________________________________________
You can take organic chemistry.
Thank you so much for all your help, I appreciate you all for helping students like me.

Click here to see answer by stanbon(75887)

Question 265863: If m varies directly as x and m = 60 when x = 5 then k, the constant of variation is..?

Click here to see answer by Ruli(21)

Question 267177: how do you prove that the quadratic formula is irrational

Click here to see answer by Edwin McCravy(20054)

Question 277572: 1. (Q∨R)→(W∨U)
2. W→P
3. Q∙T
4. U→Z
5. S→M
6. S∨~Y
7. (P∨Z)→~M ∴ ~Y
8. Q 3, simp
9. Q∨R 8, ADD
10. W∨U 1,9 MP
11. P∨S 10,2,4 CD
(I have completed lines 8-11 myself, but I cannot get past that. Thanks.)

Click here to see answer by jim_thompson5910(35256)

Question 278310: 1. (Q∨R)→(W∨U)
2. W→P
3. Q∙T
4. U→Z
5. S→M
6. S∨~Y
7. (P∨Z)→~M ∴ ~Y
Click here to see answer by jim_thompson5910(35256)

Question 277579: The outside of an unpainted 3cm by 4cm by 5cm cuboid is painted blue. It is then cut into 1cm cubes. How many of the 1cm cubes have no paint on them? Establish a rule for a cube a cm by b cm by c cm.
Click here to see answer by solver91311(24713)

Question 285690: complete the following proofs using only the Rules of Inference,The conclusion appears after the slash.
1) 1. M -> T
2. G v M
3. ~G / T

-> : means if, then
Click here to see answer by richwmiller(17219)

Question 287827: A man leaves point A at 8 am and arrives in point B at 8pm. The next day he leaves point B at 8am and arrives in point A at 8 pm. Question: is there a location anywhere between points A and B that he passed at exactly the same time, regardless of any fluctuations of speed in his journey? If so, how can it be proved?
Click here to see answer by richwmiller(17219)

Question 288258: if something is 40.76% of 51300, what % of 57000?
Click here to see answer by mananth(16946)

Question 291662: can you please help me to solve these 3 logic questions?
Question 1: do the proof to the unabbreviated theorem
~Q -> ~(P^Q)

Click here to see answer by richwmiller(17219)

Question 293878: Use an ordinary proof to solve
1) 1.E ⊃ (S ⊃ T)
2.(~L ⋅ M)⊃(S ⋅ E)
3.~ (T v L) /~M
Click here to see answer by richwmiller(17219)

Question 293877: Use an ordinary proof to solve
1) 1.E ⊃ (S ⊃ T)
2.(~L ⋅ M)⊃(S ⋅ E)
3.~ (T v L) /~M
Click here to see answer by richwmiller(17219)

Question 293881: Using an ordinary proof (not a conditional or indirect proof)

Click here to see answer by richwmiller(17219)

Question 293882: Using an ordinary proof (not a conditional or indirect proof)
1. S ⊃ (K ⋅ F)

Click here to see answer by richwmiller(17219)

Question 295266: I know it's a lot, but I've got no where else to go. Please.
> is an if/then symbol
Construct a formal proof of validity for each of the following arguments using either indirect of conditional proof:
1) 1. S>(B>T)
2. N>(T>~B) conclusion: (S & N)>~B

Click here to see answer by richwmiller(17219)

Question 296755: I have tried this several ways and cant' get it .
1.(G*P)->K
2.E->Z
3.~P->~Z
4.G->(EvL) :. (G*~L)->K
Click here to see answer by jim_thompson5910(35256)

Question 297185: Please help me solve this logic proof:
1. E→H
2. (E ∨ F) � (E ∨ G)
3. (F � G) → H conclusion is H

Click here to see answer by jim_thompson5910(35256)

Question 297359: could someone please help me with this logic proof?
1. F -> G
2. F v G conclusion G

Click here to see answer by jim_thompson5910(35256)

Question 297361: Please help with this logic proof:
1. E v T
2. T -> (B * H)
3. (B v E) -> K conclusion K
Click here to see answer by jim_thompson5910(35256)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485