A jar contains a mixture of milk and water, having 50% water. A part of this mixture is replaced by another mixture having 29% water. The percentage of water in the jar after replacement is 36%. What fraction of the original mixture was replaced?

A

$$\frac{3}{2}$$

B

$$\frac{4}{5}$$

C

$$\frac{1}{3}$$

D

$$\frac{2}{3}$$