Part 1.2 on Necessary and Sufficient Conditions (Lecture 4)

• For each part, decide whether the first member of the pair is either a necessary condition for the second, a sufficient condition, both necessary and sufficient condition, or neither.

• The following examples show the format of answers.

• Assessment weight: 4% (1% for each)

1. Joshua has a driving license. Joshua has a Lamborghini.

2. X is being smaller than 48. X is being greater than 19.

3. Being a Pembroke Welsh Corgi. Being a mammal.

4. Tiffany has a sister-in-law. Tiffany has four sisters.

Example 1 Being a tall person. Being a successful person. Answer: Being a tall person is neither a necessary nor a sufficient condition for being a successful person. A tall person is not necessarily a successful person. Also, a successful person can be a short person. Marking scheme: Correctly determine the relationship between the members of the pair: 1% Example 2 X has a smell. X smells like fish. Answer: X smells like fish is a sufficient condition for X has a smell. On the other hand, X has a smell is a necessary condition for X smells like fish. If X doesn't have a smell, then it is impossible for X to smell like fish. Marking scheme: Correctly determine the relationship between the members of the pair: 1%