Two period consumption model

In the two-period consumption model, suppose that Y1 = 100 and Y2 = 210. There is no initial wealth. If the utility function of the individual is U = log(C1) + .9 log(C2) and the interest rate is 5%, what are C1 and C2? How would your answer change if U = log(C1) + log(C2)? Explain in words why the change would happen