Question 3
Complete
Which of the following arguments are deductively valid and which are invalid?
Each argument is worth 1.0 pt., for a total of 8.0 pts.
4.0 points out of
8.0
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If you marry, you will regret it. If you do not marry, you will regret it. So, whether you marry
or do not marry, you will regret both.
valid
question
In America, in order to be successful, you must be virtuous and willing to work hard. Thus,
all successful Americans are virtuous and willing to work hard.
invalid
In America, in order to be successful, you must be virtuous and willing to work hard. Thus,
any American who is not successful is not virtuous or not willing to work hard.
valid
The closer two hedgehogs get, the more likely they are to poke each other with their spikes;
but if they remain apart, they will be lonely. So it is with people: being close to someone
inevitably creates conflicts and provocations and opens us to a lot of pain; but on the other
hand, we're lonely when we stand apart.
invalid
Either we become close to others or we stand apart. If we become close to others, we
suffer conflict and pain. If we stand apart, we'll be lonely. Therefore, we are doomed to
either suffer conflict and pain, or be lonely.
invalid
Three is a magic number. Here's why:
It takes three legs to make a tripod, or to make a table stand. It takes three wheels to
make a vehicle called a tri-cycle. Every triangle has three corners. Every triangle has three
sides. No more no less. You don't have to guess. When it's three you can see it's a
magic number.
invalid
VS.
Witches are things that weigh the same as a duck. This
woman here does not weigh the same as a duck.
Logically, then, this woman is not a witch.
valid
1. If Patrick turns evil, then SpongeBob will cry.
2. If SpongeBob cries, Squidward will rejoice.
3. Therefore, if Squidward rejoices, then Patrick will turn evil.
valid
