When dealing with probabilities, and AND means multiply and an OR means add.
For each marble color, there is a probability that Fernando will pick that color out of the bag: (# of color)/(total marbles). Since he puts the marble back each time, the number of total marbles stays the same for each draw.
The probability that Fernando will get a green OR blue on the first draw AND a pink on the second draw is:
( (green probability) + (blue probability) ) × (pink probability).
For example:
There are 10 marbles in the bag (5 green, 1 blue, 4 pink)
The probability Fernando will pull a green OR blue on the first pull AND pink on the second is:
(5/10 + 1/10) × 4/10
Which equals: 6/10 × 4/10
Which equals: 6/25
