1. **State the problem:** There are 640 students in total. \frac{3}{10} use their own vehicles, \frac{5}{8} use public transport, and the rest come on foot. We need to find how many students come on foot. 2. **Formula and approach:** Total students = Students using own vehicles + Students using public transport + Students coming on foot. 3. **Calculate students using own vehicles:** $$640 \times \frac{3}{10} = 192$$ 4. **Calculate students using public transport:** $$640 \times \frac{5}{8} = 400$$ 5. **Calculate students coming on foot:** Total students - (Students using own vehicles + Students using public transport) $$640 - (192 + 400) = 640 - 592 = 48$$ 6. **Answer:** 48 students come on foot.