Calculate the number who passed from each group, then the overall percentage.<br><br>\\(\begin{aligned}<br>\text{Boys passed} &= 80\% \times 250 = 0.80 \times 250 = 200<br>\\<br>\text{Girls passed} &= 90\% \times 200 = 0.90 \times 200 = 180<br>\\<br>\text{Total passed} &= 200 + 180 = 380<br>\\<br>\text{Total students} &= 250 + 200 = 450<br>\\<br>\text{Overall pass rate} &= \frac{380}{450} \times 100\% = 84\frac{4}{9}\%<br>\end{aligned}\\)<br><br>Final Answer: 380 students passed; \\(84\frac{4}{9}\%\\) overall pass rate