The Giant Soup Can Puzzle

Due on Nov 13^th

To sovle this puzzle, I printed out the photo which has the bicycle and the water tank. I measured the length and height of the bike and the length of the water tank with ruler (I am not sure if this is the right way). I wasn’t comfortable using the ratio between the height of the bike and the width of the tank in the picture because the way the bike was positioned.   I found two ratios: the height of the bike over the length of the bike (3/5) and the length of the bike over the length of the water tank (2/5) approximately.  I manipulated the ratio equations so that the dimensions and the volume of tank can be represented by the height of the bike (since it was given). 

First, I found the length of the tank by substitution.  Then, after doing some research, I knew that the actual size of a Campbells’ soup can has dimensions of 41 cm and 51cm. This ratio can be used to find the width of the tank.  Once the width and length of the water tank were identified, the volume of it was easily found by using cylinder volume formula. The final answer was quite award (I might misunderstand the question) because the fractions looked really large, but it was an interesting experience.   As for now, I still don’t know whether my approach was right or wrong.  In the end, I found from the website that an average size of a bike has a length of 68 inches (about 170 cm).   Using my previous formula, I fou nd that the volume of the tank was about 40.12 cubic meters.  Then I researched on how much water needed to put out a single-family house fire.  The result showed that to effectively control a house fire with 100% involvement, it required about 400gpm water.  I did the conversion once again and it seemed that the tank contained enough water to put out the house fire. 

From a student’s perspective, one would like to have concrete numbers given in the questions.  However, taking from a teacher’s perspective, by not showing any numbers, the students have to research on the information needed to solve this puzzle and have to make logic conclusion whether the water tank will contain enough water to put out a house fire.  This approach will provide students opportunities to take initiatives in their learning and find out reasonable solutions by doing research.

To extend this puzzle, I could choose triangle or semicircle as the base shapes. I can link them to the real-life architectures such as pyramid or temples and use pyramid and semicircle shaped trees as comparison.  Since tress have the length of the truck which don’t belong to the shape to be compared with, it may add another layer of difficulty but also more interesting.