Tea Bags

As the contents of the jar are used up, when each joined pair is taken out a single bag is put back in the jar, which is eventually consumed.  Suppose the jar holds 40 tea bags in joined pairs; then between refillings of the jar, 20 double bags and 20 single bags will be taken out.  In other words, Elysia will always pull out a double bag 50% of the time.  So her chances of extracting a double bag or a single bag are equal.