Fewer or less?

Some pairs of words are easily confused because they have similar meanings. See if you can choose the correct word in the examples below. It's not as easy as it sounds!

1. Can you express that in 500 words or Placeholder for the answer?
2. I stood in the "10 items or Placeholder for the answer" line in the supermarket for 10 minutes.
3. The correct answer to this math problem is x is Placeholder for the answer than 12.
4. You need to correctly answer no Placeholder for the answer than 15 of the math problems to pass this exam.
5. Greater emphasis on health issues means that there are Placeholder for the answer people eating candy.
6. You will be assigned Placeholder for the answer work this week.
7. The Department of National Defence has bought Placeholder for the answer computers this year than last.