This is a problem involving comparisons; when you have a problem like that, is a good idea to compare two things at the time.
Let's compare our subjects
- Since David is taller than Chris and Chris is shorter than Anne, Anne is shorter than David (or David is taller than Anne).
- Since Chris is shorter than Anne and Anne is as tall as Sarah, Chris is also Shorter than Sarah.
- Since Sarah is shorter than David and Chris is Shorter than Sarah, Chris is also shorter than David.
From the first and third sentences we can infer that Chris is shorter than David. From the second sentence we can infer that Chris is shorter than Anne. From the second sentence we can infer that Chris is shorter than Sarah. Chris is shorter than everyone!
We can conclude that the shorter person is Chris.
In addition, we can follow a similar pat to discover who is the tallest:
We already know that the shorter person is Chris; since Anne and Sarah are taller than David and David is taller than Anne and Sarah, David is the tallest person. Sarah and Anne tie in second place.
