A jug is a frustum with top radius 7 cm, bottom radius 3.5 cm and height 12 cm…

Step 1. The bracket. $R^2 + Rr + r^2 = 49 + 24.5 + 12.25 = 85.75\ \text{cm}^2$.

Step 2. The volume. $\dfrac{\pi \times 12\ \text{cm}}{3} \times 85.75\ \text{cm}^2 = 343\pi\ \text{cm}^3 = 1077.6\ \text{cm}^3$, which is $1077.6\ \text{mL}$.

Step 3. The number of jugs. $5000 \div 1077.6 = 4.64$.

Step 4. Full jugs. Only whole jugs count, so $4$ jugs are filled completely.