Well MH,
your number belongs to a particular colour.
Good start !
then your are asked to choose among five houses where each house has only one number of each colour.
Er yes.
its easy to find which number you have chosen.
Following you so far.
e.g. 7, 8, 11, 19 and 24 are black in colour and each house has one of these numbers. in second click you tell your colour. as soon as you choose the house (A/B/C/D/E) you are disclosing your number.
No problem yet.
now opening the door is a simple software which shows a particular number behind that door, which you click first. isn't it ?
But that's the clever bit - that needs explaining !
Have you not seen that all three of the last doors have numbers behind them - and ONLY the first one clicked is the correct one ?
You need to explain that mystery - before you are awarded any mathematical prize !
6 out of 10 for trying !