CS2104: Introduction to Problem Solving
Homework Assignment 3

Due at 8:00AM on Friday, September 09
30 Points

Here are the problems for Homework 3. Note: “About face” means to turn 180 degrees, to face in the opposite direction. “Turn left” or “turn right” means to turn 90 degrees in the named direction.

  1. You are facing south. You turn left, make an about-face, turn right, and turn right again. Which direction is behind you?
  2. You are facing northeast and make an about-face. Which direction is on your right?
  3. Gladys is a teacher, Sally a truck driver, Violet a crane operator, and Hannah a Hollywood stuntwoman. The truck driver is heavier than Hannah. The crane operator is lighter than the stuntwoman. Gladys is heavier than the truck driver. Which woman is the heaviest and which is the lightest?
  4. Dracula hates daylight more than the Wolfman unless Frankenstein hates daylight more than Dracula. In that case Wolfman hates daylight more than Dracula but less than Mummy. Mummy hates daylight more than Dracula but less than Frankenstein. Show a diagram of the monsters ordered according to their hatred of daylight.
  5. (Making a table should help the solver here.)
    Four lawn care fanatics, Fred, John, Alice, and Nina between them own 86 grass cutting devices consisting of shears, string trimmers, and power mowers. Fred likes to be close to his work, so he owns 8 shears and 13 string trimmers, but no mower. John is just the opposite. He prefers to stay as far from the work as possible and therefore owns only power mowers, 33 in all! Alice is an all-around gardener who owns 5 shears, 8 power mowers, and various string trimmers. Nina, a woman of many talents, has a total of 15 implements, among which are 3 shears and 5 string trimmers. Interestingly, the four fanatics own more than twice as many mowers as string trimmers, 48 mowers in all. How many string trimmers does Alice own?
  6. (In addition to describing the steps taken to solve the problem, show a table of person vs. type of dresses with the numbers of dresses completely filled in.)
    Three women — Pat, Joan, and Mary — have between them a total of 30 dresses of which 15 are cotton and the rest are either wool or synthetic fiber. Pat has 3 cotton dresses, 3 synthetics, and no wool dresses. Mary, who has a total of 8 dresses, has 4 cotton dresses. Joan has as many wool dresses as Pat has cotton dresses. And Mary also has as many wool dresses as Pat has cotton dresses. How many total dresses does Joan have?