A certain weak base has a Kb of 5.8 x 10^-6. What concentration of this base would have a pH of 10.92

A certain weak base has a base ionization equilibrium constant Kb of 5.8 x 10^-6. What concentration of this base would have a pH of 10.92?

Thanks!

since pH + pOH = 14

at a pH of 10.92, the pOH = 3.08
so
[OH-] = 10^-3.08
[OH-] = 8.32 X 10^-4 Molar

base in water ==> BH+ & OH-

Kb = [BH+] [OH-] / [B]

5.8 X 10^-6 = [8.32 X 10^-4] [8.32 X 10^-4] / [B]

[B] = (6.92 X 10^-7) / (5.8 X 10^-6)

[B] = 0.12 Molar