Applied online and got an interview in a month. There were two rounds of phone interviews with two software engineers.

The first interview was five minutes late, but the interviewer ended on time. The interview question was hard.

The second interview was okay.

The vending machine has three buttons: A, B, and C. When you press a button, there is a range of volume of drink you will get.

For example:

A: 200 ml - 210 ml B: 500 ml - 510 ml C: 700 ml - 710 ml

You have a bottle with a lower and upper range. You can press any buttons multiple times, but you must ensure that once you get a soda, you pour it into the bottle. Make sure all the soda you get falls within the range of the bottle.

Find all combinations of buttons to press that allow you to fill your bottle.