So you need to find the volume in L? If so:
Convert the mass of Lithium Bromide into moles by dividing the 100 grams by the molar mass of LiBr, taken from the periodic table
In a solution, moles = (concentration in mole/L) x (volume in L)
We know the moles, we have the concentration in mole/L, now find the volume in L, and you should get 0.288. Plz do the math and check for yourself