Recap - Silver Bromide Test

A plant chemist checks each batch of Dead Sea brine by adding silver nitrate solution, which turns its bromide into a pale yellow solid, silver bromide:

Ag⁺(aq) + Br⁻(aq) → AgBr(s)

$40\ \mathrm{mL}$ of the brine (0.050 M Br⁻) is mixed with $30\ \mathrm{mL}$ of $0.050\ \mathrm{M}$ silver nitrate solution. What mass of silver bromide, AgBr, forms?