I am not sure if i have a firm grasp on dependent and independent samples.

I am needing help with these three questions. I am not sure if i have a firm grasp on dependent and independent samples. These are the last three on my assignment.

In order to compare two scales, 30 objects are weighed on both scales. Each object would then have two weight values (one from scale 1 and one from scale 2). Based on the nature of the differences in the two weight measurements for the 30 objects, the two scales may be compared. Do these samples represent dependent or independent samples?

Describe how one could select two dependent samples from among his/her co-workers in General Motors to compare their starting salaries after graduation from high school to their salaries when they continue working at GM and reach the age of 40.

A group of sheep, infested with tapeworms, are randomly divided into two groups as follows. Each sheep is assigned a number (1 through 20) and then 10 numbers are selected by drawing 10 slips of paper from a box having the numbers 1 through 20written on them. The drawing divides the sheep into two groups. One group is given a placebo and the other is given an experimental drug. After six weeks the sheep are sacrificed and tapeworm counts are made. Do these samples represent dependent or independent samples?