How is the zakat calculated for an amount of (10,0) Egyptian pounds saved since Ramadan 5, 1424 AH, and an additional amount of (8,0) Egyptian pounds obtained on Rabi' al-Awwal 10, 1425 AH, and when is the zakat due?

If the second wealth is a result of the first, like profit, then both are considered a single wealth, and zakat becomes obligatory on it when a full year has passed on the principal, provided it reaches the minimum threshold (nisab). However, if the second wealth is independent, then zakat is obligatory on each wealth when its own year has passed. The amount that must be given is a quarter of a tenth (2.5%).