The two substances combined to form a new substance.
Explanation:
In the context, it is given that Mary has two beakers A and B. Beaker A is filled with a colorless liquid while that of beaker B consists of a liquid which is blue in color. Therefore the two beakers have two different substances. When substance from the beaker B is added to beaker A, a solid is formed which is pink in color. Thus we can conclude that when the substance form beaker B i.e. the pink liquid is mixed with the substance in beaker A, a new substance is formed. Therefore, the two substances combines and forms a new substance.
