Bob and Alice have bought a piece of land – 300m2 to be precise. When they ask for its proportions they are told it’s a rectangle and it’s four times longer than it’s wide. Bob now knows enough to calculate the two sides. How wide and long is it?
After Bob is finished with the calculations they find out that the ground is located on an old mine, which can collapse at any moment. Alice wants to know how much pressure is currently on the ground by calculating the density of the air above to a maximum of 4 km. She knows that the air consists of 80% N2 and 20% O2. She has found the density of O2 to be 1429*10-3 kg/m3 and the density of N2 to be 1251*10-3 kg/m3.
Despite the shocking result Bob and Alice want to build a little shack. They order one (pre-built of course). They read the description: “Shack: 162m3. Imagine this shack as a 3D-cube. The second side (y) is twice as long as the first (x) and the third (z) is three times longer than the first (x). The second side (y) is 7m.” But Bob and Alice have figured it out to be wrong. Why is it wrong and how long are all three sides then?
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