Unit 4 Answers

1.

1. If there is an inch of snow on the street, the newspaper will not come.
2. If the wind blows from the northeast, then it snows.
3. If prices go up, then supply will be plentiful.
4. If you are going to understand the materials of this course, you must read the textbook.
5. If a number is the sum of three consecutive integers, then it is divisible by 3.
6. If you guarantee is good, then you must have bought your TV less than 90 days ago.

2.

1. You drink a lot of water if and only if it is hot outside.
2. A program is readable if and only if it is well structured.
3. I like fruits if and only if they are fresh.
4. Your teeth will decay if and only if you eat too much sweets.
5. The store is closed if and only if it is the day when I want to shop there.