First off, when I say real, I do not mean in the sense that some questions exist, and others do not. I mean real in the sense of integer, rational and real numbers.
No the other kind of question is a multiple choice question. While multiple choice questions are essential for navigation and action within the game, and they provide educational value, they are not included in the final score calculation.
At the core of every Stimsims game, is a simulation calculated with a set of randomized variables. All data and multiple choice questions are calculated from these seed values. To solve the problem, the player must analyze the exposed information about the simulation, to deduce the hidden solutions that will win the game. Multiple choice questions allow the player to measure the simulation, build and operate on equations, but ultimately, only the solutions of these equations are judged in the final score.
Many multiple choice questions are sequenced steps in a math operation. For example, if the player chooses the wrong initial math equation in this sequence, the game will let the player know they were wrong, but will proceed with their mistaken equation in calculations until the sequence is complete. The game will generate the next multiple choice questions with the players mistake. As such, in the subsequent questions about how to operate on this incorrect equation, the player can still get a correct technical answer, while deriving an incorrect solution.
In other words, one mistake in the players working doesn't prevent them from answering subsequent questions correctly, even if it results in an inaccurate solution, and therefore a low final score.
There are two reasons.
Technologically: in exam mode (coming soon), the secret, randomized, unknown simulation variables are stored on the Stimsims server, and are never sent to the players device. This makes it impossible to cheat in exam mode. Multiple choice questions and their answers are not cheat-proof, and therefore are not trusted for the players final score.
Metaphysically: exactly how you come to a solution isn't all that important (I am not a doctor so don't @ me). What matters is that your estimation of this secret, randomized, unknown parameter is accurate. Stimsims games model their scores accordingly.