What is the percentage of the sister's share of the profit, if she contributed 30,0 to a project that the other sister worked on alone for two years without a salary, while she contributed 60,0 and did not work on the project at all?

The transaction described is a permissible company (partnership) and mudarabah (profit-sharing). However, the failure to agree upon each partner's share of the profit invalidates the contract. In such a case, the worker is entitled to a fair wage (ujrat al-mithl), and the profit is divided between them according to each one's share of the capital. It is stated in Ibn Qudamah's Al-Mughni: "Among the conditions for the validity of mudarabah is the determination of the worker's share," and that "The ruling for partnership is like the ruling for mudarabah, in the necessity of knowing the amount of profit due to each one of them." If the partnership becomes invalid, they divide the profit according to the proportion of their capital contributions, and the worker is entitled to a fair wage. However, if the work was done gratuitously (as a voluntary act), the worker is not entitled to a wage.