If x = 1 + log 2 - log 5, y = 2 log 3 and z = log a - log 5; find the value of a, if x + y = 2z.

If x = log 0.6; y = log 1.25 and z = log 3 - 2 log 2, find the values of :

(i) x + y - z

(ii) 5^{x + y - z}