Question

What are the answers to these statements related to the concepts of sufficient and necessary conditions?

1. Unless you are unmarried, you are not a bachelor.
“You are not unmarried” is a __________ condition for “You are not a bachelor”.

2. “It is impossible for a healthy person not having a rest; however, it could be possible for an unhealthy person resting all-day.”
From the above mentioned, “resting” is the __________ condition of “being healthy”.

3. Unless you can read, you are not a reader. Only if you are a reader, you can read.
“You cannot read” is a __________ condition for “you are not a reader”.

Answer 1

• A necessary condition must be present for an event to take place, but is not enough on its own to guarantee its ocurrence.
• A sufficient condition is such that, if present, it triggers the ocurrence of an event.

Question 1

It is a sufficient condition. If a person is not unmarried, therefore is married. This is sufficient to claim that this person is not a bachelor.

Question 2

Resting is a necessary condition for being healthy. As the text states, resting properly is a habit that must be present if someome wants to have a healthy lifestyle. But, it also states that on its own, resting cannot ensure good health, as people with bad health might also rest all day.

Question 3

It is a sufficient condition. If a person can read, automatically becomes a reader, and therefore the opposite applies too: if a person cannot read, is not a reader.