Unit 4 Excercise

Textbook p.12:

15. Write each of the following statements in the form "if p, then q" in English.   (Hint: Refer to the list of common ways to express implications listed in this section.)

  1. It snows whenever the wind blows from the northeast.
  2. The apple trees will bloom if it stays warm for a week.
  3. That the Pistons win the championship implies that they beat the Lakers.
  4. It is necessary to walk 8 miles to get to the top of Long's Peak.
  5. To get tenure as a professor, it is sufficient to be world-famous.
  6. If you drive more than 400 miles, you will need to buy gasoline.
  7. Your guarantee is good only if you bought your CD player less than 90 days ago.

17. Write each of the following propositions in the form "p if and only if q" in English.

  1. If it is hot outside you buy an ice cream cone, and if you buy an ice cream cone it is hot outside.
  2. For you to win the contest it is necessary and sufficient that you have the only winning ticket.
  3. You get promoted only if you have connections, and you have connections only if you get promoted.
  4. If you watch television your mind will decay, and conversely.
  5. The trains run late on exactly those days when I take it.

 

Answers for these exercises