💡Tired of Studying?There's a shortcut.
Hire an expert to take your LSAT!Invalid Argument Forms
Invalid Argument Forms
Invalid Argument Form (1 of 7)
Take a break with this short comic.
And another one with this short comic.
Invalid Argument Form (2 of 7)
Invalid Argument Form (3 of 7)
Invalid Argument Form (4 of 7)
Typo in the video (second sentence): Most men like hate driving
Invalid Argument Form (5 of 7)
Invalid Argument Form (6 of 7)
Invalid Argument Form (7 of 7)
Distinguish Valid from Invalid Forms
Arguments Summary
Quiz on Drawing Valid Conclusions 1 w/ Answers
Quiz Instructions: Using all relevant premises, draw all possible inferences. Including all "trivial" inferences.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original M → P _______
Answer
M → P
_______
M −m→ P
M ←s→ P
/P → /M
/P −m→ /M
/P ←s→ /M
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /F → R _______
Answer
/F → R
_______
/F −m→ R
/F ←s→ R
/R → F
/R −m→ F
/R ←s→ F
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original G → O G _______
Answer
G → O
G
_______
O
G −m→ O
G ←s→ O
/O → /G
/O −m→ /G
/O ←s→ /G
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /I → K /K _______
Answer
/I → K
/K
_______
I
/I −m→ K
/I ←s→ K
/K → I
/K −m→ I
/K ←s→ I
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original F → E D → /E _______
Answer
F → E
D → /E
_______
F → /D
F −m→ /D
F ←s→ /D
D → /F
D −m→ /F
D ←s→ /F
F −m→ E
F ←s→ E
/E → /F
/E −m→ /F
/E ←s→ /F
D −m→ /E
D ←s→ /E
E → /D
E −m→ /D
E ←s→ /D
Quiz on Drawing Valid Conclusions 2 w/ Answers
Quiz Instructions: Using all relevant premises, draw all possible inferences. Do NOT draw "trivial" inferences.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original
G → B
/B → /H
G
_______
Answer
G → B
/B → /H
G
_______
B
/G ←s→ /H
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original
/B → /R
/S → /R
R
_______
Answer
/B → /R
/S → /R
R
_______
S
B
B ←s→ S
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original
/T → B
/U → /B
/U
_______
Answer
/T → B
/U → /B
/U
_______
/B
T
/U → T
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original
G → W
W → J
J
_______
Answer
G → W
W → J
J
_______
G → J
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original
/U → X
U → /Y
/H → /U
H → E
/X
_______
Answer
/U → X
U → /Y
/H → /U
H → E
/X
_______
E
H
/Y
U
/Y ←s→ H
/Y ←s→ E
Y → X
/H → X
/E → /U
/E → X
Quiz on Drawing Valid Conclusions 3 w/ Answers
Quiz Instructions: Using all relevant premises, draw all possible inferences. Do NOT draw "trivial" inferences.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original M → P V → M M _______
Answer
M → P
V → M
M
_______
P
V → P
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original Y → /X X → H Q → /H /H → Z /H _______
Answer
Y → /X
X → H
Q → /H
/H → Z
/H
_______
/X
Z
/X ←s→ Z
Q → /X
Q → Z
/Y ←s→ H
/Y ←s→ /Q
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /R → /E R _______
Answer
/R → /E
R
_______
only trivial inferences
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original M → F /J → /M /F _______
Answer
M → F
/J → /M
/F
_______
/M
F ←s→ J
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original M → H H → B _______
Answer
M → H
H → B
_______
M → B
Quiz on Drawing Valid Conclusions 4 w/ Answers
Quiz Instructions: Using all relevant premises, draw all possible inferences. Do NOT draw “trivial” inferences.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original U → T Y → /T U _______
Answer
U → T
Y → /T
U
_______
T
/Y
U → /Y
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original G → U /U → H _______
Answer
G → U
/U → H
_______
/G ←s→ H
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original U → J /U _______
Answer
U → J
/U
_______
only trivial inferences
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /O → P /P → Z /Z _______
Answer
/O → P
/P → Z
/Z
_______
P
O ←s→ Z
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original W → Q F → /Q /F _______
Answer
W → Q
F → /Q
/F
_______
W → /F
Quiz on Drawing Valid Conclusions 5 w/ Answers
Quiz Instructions: Using all relevant premises, draw all possible inferences. Do NOT draw “trivial” inferences.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /X → M /M → Z U → /Z Z _______
Answer
/X → M
/M → Z
U → /Z
Z
_______
/U
U → M
X ←s→ Z
X ←s→ /U
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original G → H H → B B → Z /H → Y /H _______
Answer
G → H
H → B
B → Z
/H → Y
/H
_______
/G
Y
/G ←s→ Y
Question 3
Tap to restore original J → C /C → /H C _______
Answer
J → C
/C → /H
C
_______
/J ←s→ /H
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original K → /L /M → /L C → K M _______
Answer
K → /L
/M → /L
C → K
M
_______
C → /L
/K ←s→ M
/C ←s→ M
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original F → Z Z → K M → U /U → P P → Z _______
Answer
F → Z
Z → K
M → U
/U → P
P → Z
_______
P ←s→ /M
Z ←s→ /M
K ←s→ /M
/F ←s→ /P
/F ←s→ U
Quiz on Drawing Valid Conclusions with Translations 1 w/ Answers
Quiz Instructions: Translate all English statements into Lawgic. If possible, combine premises. Draw all valid conclusions. Translate conclusions back into English.
Question 1
Tap to restore original No Jacksons are non-swimmers. Andrew is a Jackson.
Answer
No Jacksons are non-swimmers. Andrew is a Jackson.
_______
Andrew is a swimmer.
Question 2
Tap to restore original Gods of Mt. Olympus watch the Olympics. Those who watch the Olympics like to eat wasabi. Hermes is a god of Mt. Olympus.
Answer
Gods of Mt. Olympus watch the Olympics. Those who watch the Olympics like to eat wasabi. Hermes is a god of Mt. Olympus.
_______
Hermes likes to eat wasabi.
Question 3
Tap to restore original If magicians are real, then pastries do cook themselves. If the birds can sing, then magicians are real.
Answer
If magicians are real, then pastries cook themselves. If the birds can sing, then magicians are real.
_______
The birds cannot sing unless pastries cook themselves.
Question 4
Tap to restore original No one is invited who did not RSVP. Rudy did not RSVP.
Answer
No one is invited who did not RSVP. Rudy did not RSVP.
_______
Rudy is not invited.
Question 5
Tap to restore original The ume blooms from December to January only. Only trees that bloom for three or more months are amenable to the tastes of the emperor.
Answer
The ume blooms from December to January only. Only trees that bloom for three or more months are amenable to the tastes of the emperor.
_______
The ume is not amenable to the tastes of the emperor.
Quiz on Drawing Valid Conclusions with Translations 2 w/ Answers
Quiz Instructions: Translate all English statements into Lawgic. If possible, combine premises. Draw all valid conclusions. Translate conclusions back into English.
Question 1
Tap to restore original All of our company’s flashlights are made from LED bulbs. No LED bulbs are fluorescent. The bulbs in the theater are not fluorescent.
Answer
All of our company’s flashlights are made from LED bulbs. No LED bulbs are fluorescent. The bulbs in the theater are not fluorescent.
_______
None of our company's flashlights are fluorescent.
Question 2
Tap to restore original Without the aid of monkeys, we could not have explored space. Space exploration necessitates an understanding of general relativity. Understanding general relativity implies understanding Newtonian mechanics is inaccurate. Einstein understood general relativity.
Answer
Without the aid of monkeys, we could not have explored space. Space exploration necessitates an understanding of general relativity. Understanding general relativity implies understanding that Newtonian mechanics is inaccurate. Einstein understood general relativity.
_______
Einstein understood that Newtonian mechanics was inaccurate.
We could not have explored space without understanding that Newtonian mechanics was inaccurate.
Question 3
Tap to restore original Only roses are red. Only thorny things are red. There's a red thing in the flower garden.
Answer
Only roses are red. Only thorny things are red. There's a red thing in the flower garden.
_______
There's a rose in the flower garden.
There's a thorny thing in the flower garden.
Some roses are thorny.
Question 4
Tap to restore original If Serena likes Dan, then Blair likes bricks. Serena doesn’t like Dan.
Answer
If Serena likes Dan, then Blair likes bricks. Serena doesn’t like Dan.
_______
nothing interesting here
Question 5
Tap to restore original Yaks don’t like to drink cow’s milk. Peasants, who do like to drink cow’s milk, are happy. Quest-bound Princes are not happy. Unhappiness always leads to frustration. Aladdin is not happy.
Answer
Yaks don’t like to drink cow’s milk. Peasants, who do like to drink cow’s milk, are happy. Quest-bound Princes are not happy. Unhappiness always leads to frustration. Aladdin is not happy.
_______
Aladdin is not a peasant.
Aladdin is frustrated.
Some frustrated people are not peasants.
Some happy people like to drink cow's milk.
Some happy people are not yaks.
Some people who are not quest bound princes like to drink cow's milk.
Some people who are not quest bound princes are not yaks.
Quiz on Drawing Valid Conclusions with Translations 3 w/ Answers
Quiz Instructions: Translate all English statements into Lawgic. If possible, combine premises. Draw all valid conclusions. Translate conclusions back into English.
Question 1
Tap to restore original Trader Joe’s sales clerks like to talk. No soccer mom doesn’t like to talk. Baseball moms are soccer moms. Jane is a soccer mom.
Answer
Trader Joe’s sales clerks like to talk. No soccer mom doesn’t like to talk. Baseball moms are soccer moms. Jane is a soccer mom.
_______
Jane likes to talk.
Baseball moms like to talk.
Some people who are not Trader Joe's sales clerks are not soccer moms.
Some people who are not Trader Joe's sales clerks are not baseball moms.
Question 2
Tap to restore original All Tiberium plants constantly emit Tiberium clouds. All Tiberium clouds kill local trees instantly. The trees in and around Washington D.C. are growing well.
Answer
All Tiberium plants constantly emit Tiberium clouds. All Tiberium clouds kill local trees instantly. The trees in and around Washington D.C. are growing well.
_______
There are no Tiberium clouds nor plants around Washington D.C.
All Tiberium plants kill local trees instantly.
Question 3
Tap to restore original When it’s not raining, NYC is hot. When it is raining, Seattle is not hot. When there are no clouds, it is raining. When there are clouds, Elephants run amok. NYC is not hot.
Answer
When it’s not raining, NYC is hot. When it is raining, Seattle is not hot. When there are no clouds, it is raining. When there are clouds, Elephants run amok. NYC is not hot.
_______
It is raining and Seattle is not hot.
Sometimes it is hot in NYC and there are clouds.
Sometimes it is hot in NYC and elephants run amok.
Question 4
Tap to restore original All koala bears are salacious. All things that cannot swim are not koala bears. Poppers isn’t salacious.
Answer
All koala bears are salacious. All things that cannot swim are not koala bears. Poppers isn’t salacious.
_______
Poppers isn't a koala bear.
Some salacious things can swim.
Question 5
Tap to restore original All dinosaurs that hunt its prey can run, swim and fly. Dinosaurs that cannot run, cannot swim or cannot fly are easy to catch and delicious to eat. Nothing can catch the Fastasaurus.
Answer
All dinosaurs that hunt its prey can run, swim and fly. Dinosaurs that cannot run, cannot swim or cannot fly are easy to catch and delicious to eat. Nothing can catch the Fastasaurus.
_______
Some dinosaurs that can run can swim.
Some dinosaurs that can run can fly.
Some dinosaurs that can swim can fly.
Some dinosaurs that cannot hunt are easy to catch and delicious to eat.
The Fastasaurus can run, swim, and fly.
Quiz on Drawing Valid Conclusions with Translations 4 w/ Answers
Quiz Instructions: Translate all English statements into Lawgic. If possible, combine premises. Draw all valid conclusions. Translate conclusions back into English.
Question 1
Tap to restore original Unless the Galactica returns from the expedition within a week, the Pegasus must alter its current patrol route. If the Pegasus adopts a new patrol route, it will be more difficult to resupply the Colonial ships.
Answer
Unless the Galactica returns from the expedition within a week, the Pegasus must alter its current patrol route. If the Pegasus adopts a new patrol route, it will be more difficult to resupply the Colonial ships.
_______
If the Galactica does not return within a week, then it will be more difficult to resupply the Colonial ships.
Question 2
Tap to restore original Climbing vines have pincer like hooks. All fungi have pincer like hooks. Magishrooms are a climbing vine.
Answer
Climbing vines have pincer like hooks. All fungi have pincer like hooks. Magishrooms are a climbing vine.
_______
Magishrooms have pincer like hooks.
Some things that are not climbing vines are not fungi.
Some things that are not Magishrooms are not fungi.
Question 3
Tap to restore original No one who writes quiz questions isn’t handsome. People who aren’t handsome are happy. Unless one is happy, one cannot loathe other people. Jason is not happy.
Answer
No one who writes quiz questions isn’t handsome. People who aren’t handsome are happy. Unless one is happy, one cannot loathe other people. Jason is not happy.
_______
Jason is handsome.
Jason does not loathe other people.
Some handsome people do not loathe other people.
Some happy people do not write quiz questions.
Question 4
Tap to restore original Smart girls do not date lazy boys. Sarah is a genius. Boys like to pick their noses. Derek is extremely attractive and lazy.
Answer
Smart girls do not date lazy boys. Sarah is a genius. Boys like to pick their noses. Derek is extremely attractive and lazy.
_______
Sarah will not date Derek.
Question 5
Tap to restore original If you are cursed with black magic you will turn into a chipmunk. You are not cursed with anything.
Answer
If you are cursed with black magic you will turn into a chipmunk. You are not cursed with anything.
_______
Who knows? Maybe you'll find another way to turn into a chipmunk, maybe you won't.
Quiz on Drawing Valid Conclusions with Intersection Statements 1 w/ Answers
Quiz Instructions: If possible, combine premises. Draw all must be true conclusions. No need to draw the "trivial" ones.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original M ←s→ S T → M _______
Answer
M ←s→ S
T → M
_______
If you drew "T ←s→ S", then see this lesson.
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /B → /D F ←s→ D _______
Answer
/B → /D
F ←s→ D
_______
F ←s→ B
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original E ←s→ R /L ←s→ R _______
Answer
E ←s→ R
/L ←s→ R
_______
no valid conclusions
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /S −m→ C S → N _______
Answer
/S −m→ C
S → N
_______
If you drew /N −m→ C, then see this lesson.
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original I → O I −m→ /P _______
Answer
I → O
I −m→ /P
_______
O ←s→ /P
Quiz on Drawing Valid Conclusions with Intersection Statements 2 w/ Answers
Quiz Instructions: If possible, combine premises. Draw all must be true conclusions. No need to draw the "trivial" ones.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /Q → /D D → W _______
Answer
/Q → /D
/W → /D
_______
Q ←s→ W
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /Y −m→ H /Y −m→ U _______
Answer
/Y −m→ H
/Y −m→ U
_______
H ←s→ U
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original X −m→ /C Q −m→ X _______
Answer
X −m→ /C
Q −m→ X
_______
nothing interesting
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /V ←s→ /F /F ←s→ N _______
Answer
/V ←s→ /F
/F ←s→ N
_______
no valid conclusions
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original G ←s→ E /S → /G H → T F −m→ T _______
Answer
G ←s→ E
/S → /G
H → T
F −m→ T
_______
E ←s→ S
Quiz on Drawing Valid Conclusions with Intersection Statements 3 w/ Answers
Quiz Instructions: If possible, combine premises. Draw all must be true conclusions. No need to draw the "trivial" ones.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original W → /R W −m→ T Y → /T /W → Q _______
Answer
W → /R
W −m→ T
Y → /T
/W → Q
_______
/Q → /R
/R ←s→ T
/R ←s→ /Y
W -m→ /Y
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /B → /D F ←s→ D /O → /F I → F _______
Answer
/B → /D
F ←s→ D
/O → /F
I → F
_______
I → O
F ←s→ B
O ←s→ D
O ←s→ B
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original X −m→ Y /Q → Z H ←s→ /Z X −m→ /Z _______
Answer
X −m→ Y
/Q → Z
H ←s→ /Z
X −m→ /Z
_______
X -m→ Q
Y ←s→ /Z
Y ←s→ Q
H ←s→ Q
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original B → Q /J → /B L → S B ←s→ L /H ←s→ L _______
Answer
B → Q
/J → /B
L → S
B ←s→ L
/H ←s→ L
_______
S ←s→ B
S ←s→ /H
S ←s→ Q
S ←s→ J
L ←s→ J
L ←s→ Q
J ←s→ Q
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original G ←s→ H L ←s→ H _______
Answer
G ←s→ H
L ←s→ H
_______
no valid conclusions
Quiz on Drawing Valid Conclusions with Intersection Statements 4 w/ Answers
Quiz Instructions: If possible, combine premises. Draw all must be true conclusions. No need to draw the "trivial" ones.
Question 1
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original A −m→ B /C −m→ /B _______
Answer
A −m→ B
/C −m→ /B
_______
nothing interesting
Question 2
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original C ←s→ B D ←s→ B G ←s→ F F → B _______
Answer
C ←s→ B
D ←s→ B
G ←s→ F
F → B
_______
G ←s→ B
Question 3
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original P ←s→ /G S −m→ K S −m→ /G _______
Answer
P ←s→ /G
S −m→ K
S −m→ /G
_______
/G ←s→ K
Question 4
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original /A ←s→ /L /L ←s→ /D _______
Answer
/A ←s→ /L
/L ←s→ /D
_______
no valid inferences
Question 5
#help
#feedback
←
↔
→
←s→
‑m→
Tap to restore original A −m→ /D B −m→ /A _______
Answer
A −m→ /D
B −m→ /A
_______
nothing interesting