A company uses 200 L of a liquid per week. The liquid can be bought in 1 L tins for 200 per tin or 10 L tins for 40 per tin. How much can be saved annually by buying in bulk?

For the smaller quantity: \text{Cost per liter (Option 1)} = \frac{$200}{200 \text{ L}} = $1/\text{L} For the larger quantity (bigger tins): \text{Cost per liter (Option 2)} = \frac{$40}{400 \text{ L}} = $0.10/\text{L}

There are 52 weeks in a year.

Cost if using Option 1 (smaller quantity): \text{Annual cost (Option 1)} = 10400 \text{ L} \times $1/\text{L} = $10400 Cost if using Option 2 (larger quantity, bigger tins): \text{Annual cost (Option 2)} = 10400 \text{ L} \times $0.10/\text{L} = $1040

\text{Savings} = $10400 - $1040 = $9360

The amount saved in a year if the bigger tins are used is \boxed{9360}$.