Are administrative expenses (such as salaries and management costs) taken into account when determining the halal profit from the father's investment in the gas station, considering that the percentage was not specified, but it was agreed to calculate workers' wages, taxes, and some expenses?

This type of contract is a Mudarabah (definition) (profit-sharing) partnership, which is permissible by scholarly consensus, but its validity is contingent upon two conditions:

1. Each participant's share of the profit must be known and specified as a common percentage (such as half or a third), not as a fixed amount. 2. All operating expenses must be deducted from the profit before its distribution, to ensure the safety of the capital.

The aforementioned agreement is not Islamically valid due to the absence of a specified profit percentage and the failure to deduct expenses before distribution. To correct it in the future, a percentage of the net profit must be specified. As for past invalid agreements, one must refer to experts to estimate the worker's share of the profit (a customary share), by asking: "If a person traded with this money, how much would they typically be given?" And that amount would be due to them, because the worker acted as a partner, not an employee.