CS2104: Introduction to Problem Solving
Homework Assignment 9

Due at 11:00pm on Tuesday, November 18
40 Points

Here are the problems for Homework 9. Each is worth 10 points.

1. Find the next member in this sequence: 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...
   What is the rule for obtaining the next member?

2. Acting on an anonymous phone call, the police raid a house to arrest a suspected murderer. They don't know what he looks like but they know his name is John and that he is inside the house. The police bust in on a carpenter, a truck driver, a mechanic and a plumber all playing poker. Without hesitation or communication of any kind, they immediately arrest the plumber. How do they know they've got their man?

3. How could a (normal, human) baby (accidently!) fall out of a twenty-story building onto the ground and live?

4. A woman drives home from work at 1:30 each working day. She normally takes an hour to get home each day, arriving at 2:30. One day she left work as usual, took the usual route, under the usual conditions. But instead of arriving home at 2:30, she arrived home at 3:30. Nothing strange happened to her -- no accident, heavy traffic, or anything like that. What explains this?