What it is about
You get several equations. They contain letters. Each letter stands for exactly one whole number between 1 and 20. You have to find out which number belongs to which letter. You enter the answer as a number on a numeric keypad. So there are no answer options to choose from.
20 tasks, 25 minutes, so about 75 seconds per task. Sources: testas.de: structure of the digital TestAS, g.a.s.t. preparation PDF (as of April 2022).
The rules
- Each letter has exactly one value between 1 and 20.
- All equations must hold at the same time.
- Plus, minus, times and divided by occur.
- Easy tasks have 2 unknowns, hard ones up to 4.
An example from our Trainer
Our own generator created this example.
(1) A + B = 26 (2) 6 + (C + B) = 36 (3) 10 − A = 4
Which numbers stand for A, B and C?
Show solution
A = 6, B = 20, C = 10.
- Equation (3) has only one unknown: 10 − A = 4, so A = 6.
- Insert into equation (1): 6 + B = 26, so B = 20.
- Insert into equation (2): 6 + (C + 20) = 36, so C = 10.
How to proceed
- Look for the equation with only one unknown. Almost every task has such a starting point.
- Insert at once. Every value you find makes another equation easier.
- Use the limits 1 to 20. For “A · B = 18” there are only a few pairs. Trying is allowed and often quick.
- For hard tasks: Sometimes you have to insert several equations into one before a number comes out. Start with the equations that describe a letter directly, for example “C = A + 2”.
- At the end, check an equation that you have not used yet. If it holds, usually everything holds.
Guessing?
Wrong answers cost no points. But guessing hardly helps here: with several letters of 20 possible values each, a hit is very unlikely. g.a.s.t. says so itself (testas.de: preparing for the digital TestAS). It is better to skip a task and have time for the next one.
Open
What exactly the input looks like on screen, and whether there are partial points if only some of the letters are right, is not described in the public sources.