What is the [CH3NH3+] of a solution which is 0.1003 M in CH3NH2 and 0.1204 M in CsOH?

Question

CH3NH2(aq) + H2O(l) « CH3NH3+(aq) + OH−(aq)

Answer 1

.....CH3NH2 + HOH ==> CH3NH3^+ + OH^-
I...0.1003............0.........0.1204
C.....-x..............x..........x
E...0.1003-x..........x........0.1204+x

Kb = (CH3NH3^+)(OH^-)/[CH3NH3^+]
Look up Kb and plug in the numbers. Solve for x = (CH3NH3^+)