Question

a bag contains 10 red marbles, 15 yellow marbles and 5 green marbles. what is the probability of drawing a red or green marble from the bag?
a (\frac{1}{2})
b (\frac{1}{4})
c (\frac{1}{6})
d (\frac{1}{8})

Explanation:

Step1: Calculate total marbles

$10 + 15 + 5 = 30$

Step2: Count favorable marbles

$10 + 5 = 15$

Step3: Compute probability

$\text{Probability} = \frac{\text{Favorable Marbles}}{\text{Total Marbles}} = \frac{15}{30} = \frac{1}{2}$

Answer:

A. $\frac{1}{2}$