“You have a birthday cake and have exactly 3 cuts to cut it into 8 equal pieces. How do you do it?”

If you haven’t heard it before, its considered a classic interview riddle. The idea being that you have to think outside the box to come up with the idea of cutting it once in x, once in y and once in the z to get something like this:

The “classic” answer to the problem

But that’s too easy. Some versions of the riddle specify that the cuts need to be straight — this makes the solution above the only correct one. However if you take away there are many possibilities. The first design I had used two parabollas, as shown here

However the math got really messy (see here for the synopsis) and I ended up with something along the lines of 12 simultaneous equations that I couldn’t figure out. Then, with the help of some crowdsourcing we came up with a much easier design with only one equation. Then the new cake design is as follows.

The math for this can be found here. So there ya go, everyone gets a fair share of cake.