2019 AMC 10B Problem 11

Let $x$ and $y$ be the numbers of green marbles in Jars $1$ and $2$, respectively. Then the total numbers of marbles in the jars are $10x$ and $9y$. The jars contain the same number of marbles, so $10x=9y$. Also $x+y=95$. Solving gives $x=45$ and $y=50$. Jar $1$ has $9x=405$ blue marbles, and Jar $2$ has $8y=400$ blue marbles. The difference is $5$. Thus, A is the correct answer.