What is the pH of solution?

This is a basic buffer and it will have a pH > 7.00. The first answer is incorrect.
For a basic buffer w3here you have pKb , the correct calculation is.
pOH = pKb + log ([salt]/[base])
pKb = -log Kb = - log (1*10^-5) = 5.0
pOH = 5.0 + log (0.05/0.10)
pOH = 5.0 + log 0.5
pOH = 5.0 + (-0.30)
pOH = 4.70
pH = 14.00 - 4.70
pH = 9.30

NH₃(aq) + H₂O(l) ⇌ NH₄⁺(aq) + OH⁻(aq) …. Kb = 1 × 10⁻⁵

pH = pKb + log([NH₄⁺]/[NH₃])
pH = -log(Kb) + log([NH₄⁺]/[NH₃])
pH = -log(1 × 10⁻⁵) + log(0.05/0.1)
pH = 4.7