A jar has 100 marbles, 60 red ones and 40 blue ones. You select 2 marbles (with replacement).

Use a decision tree for this

1. What is the probability you select a red marble on the first selection?

2. What is the probability you select one marble of each color?

3. What is the probability you select two red marbles?

4. What is the probability you select two blue marbles?

I am not even sure where to start and I don't know if I have to draw a tree for each question? Thank you!