1. **State the problem:** We have 5 vans transporting a total of $d$ kg of food. Each van transported the same amount, and this amount is at least 60 kg. 2. **Define variables:** Let $x$ be the amount of food transported by each van in kg. 3. **Write the inequality:** Since each van transported the same amount, total food is $d = 5x$. 4. **Given condition:** Each van transported at least 60 kg, so $x \geq 60$. 5. **Substitute $x$ in terms of $d$:** Since $x = \frac{d}{5}$, the inequality becomes: $$\frac{d}{5} \geq 60$$ 6. **Solve for $d$:** Multiply both sides by 5: $$d \geq 5 \times 60$$ $$d \geq 300$$ 7. **Interpretation:** The total amount of food $d$ must be at least 300 kg. **Final answer:** $$d \geq 300$$