3. (8 points) Teacher Zhang brought some money to buy pens. Upon arriving at the store, he found that the price of the pens had decreased by $25 \%$, and as a result, the money he brought could buy 25 more pens than before. How many pens could the money buy before the price drop?
【Solution】Solution: Let the original number of pens that can be bought be $x$. According to the problem, we have:
$$
\begin{aligned}
1 \times x & =(x+25) \times(1-25 \%), \\
x & =(x+25) \times 0.75, \\
x & =0.75 x+18.75, \\
0.25 x & =18.75, \\
x & =75 ;
\end{aligned}
$$

Answer: Before the price reduction, the money could buy 75 pens. Therefore, the answer is: 75.