### Home > GB8I > Chapter 10 Unit 11 > Lesson INT1: 10.2.3 > Problem10-110

10-110.

Ambrose has a bag of marbles with R red marbles, G green marbles, B blue marbles, and Y yellow marbles. Write an expression for each of the following situations.

1. The probability of selecting a yellow marble.

$\frac{Y}{R+G+B+Y}$

2. The probability of selecting a blue or green marble.

Add the blue and green together.

3. The probability of selecting a purple marble.

How many purple marbles are there?