## An interesting question for QA engineer interview

When

*interview*a*QA engineer*position I always ask a person to solve the problem like this:- Assume you have a calculator to test (what a surprize)
- This calculator has some specific
- It accepts only the digits "0" and "1" as input
- It uses decimal numeration though
- It displays a result using 0-9
- It can display decimal fraction
- However it does not accept input of decimal fraction
- It can dispay negative numbers
- However it does not accept input of negative number
- It supports the only two operations: division and substraction
- It supports sequential input without the need of pressing "=" (e.g. 10/1/10 = 1)
- It displays only 5 digits on a screen, however it accepts 6 digit input so that the most significant digit is not shown. It still takes part in calculation.

Here on the picture the example of such the calculator is shown. The number on the screen is showing one of the possible calculation results produced by the device. The task for a candidate it to :

- design as many
*test cases*for this system as possible - Select 5 cases that the candidate would run (the most important ones) if there would not be enough time for comprehesive
*testing*.

That question shows if the candidate can solve the problems which have some specific as against the well-known but resembling ones. It also shows if the candidate can ask the "right" questions and look for the relevant

*requirements*.