Probability — practice question

Rahul has two bags, $X$ and $Y$. Bag $X$ holds $4$ red marbles and $2$ blue marbles, while bag $Y$ contains $3$ red marbles and $4$ blue marbles. Rahul also has a biased coin for which the chance of getting a head on a toss is $\frac{1}{4}$. Rahul throws the coin. If a head appears, he selects one marble at random from bag $X$, notes its colour and returns the marble to bag $X$. He then selects a second marble at random from bag $X$. If a tail appears, he selects one marble at random from bag $Y$, notes its colour and discards the marble. He then selects a second marble at random from bag $Y$.