Let's work through the problem step-by-step:

Suppose the original share price is $P$.

1. First drop (20%): After the first week, the price becomes $\(P \times 0.8\)$.

2. Second drop (25%): After the second week, the new price is $\(P \times 0.8 \times 0.75=P \times 0.6\)$.

So, the current price is $0.6 P$.

To return to the original price $P$, the increase needed is $\(P-0.6 P=0.4 P\)$.

What percent of the current price is this increase?
Percent increase $\(=\frac{0.4 P}{0.6 P} \times 100=\frac{2}{3} \times 100=66 \frac{2}{3}\) %$

So, the share price must rise by $\(66 \frac{2}{3}\) %$ of its current value to return to the original price.

If you want, we can walk through similar compound percent questions together or try some practice rounds.