Question 40·Easy·Probability and Conditional Probability
A jar contains 24 red beads, 15 blue beads, and 11 green beads.
If one bead is selected at random from the jar, what is the probability that the bead selected is blue?
For basic probability questions on the SAT, always start by identifying the total number of outcomes (sum all categories given) and the number of favorable outcomes (the specific category the question asks about). Then write probability as “favorable over total” and, if needed, simplify the fraction; finally, compare your result directly with the answer choices, watching out for distractors that use the wrong denominator or count the wrong category.
Hints
Think about the total outcomes
First, how many beads are in the jar altogether? Add up the red, blue, and green beads.
Focus on the color asked for
The question asks about the probability of selecting a blue bead. How many blue beads are there?
Build the probability fraction
Probability is (number of desired outcomes) divided by (total number of outcomes). Use your numbers for blue beads and total beads to form this fraction.
Desmos Guide
Compute the probability directly
In Desmos, type 15/(24+15+11) and press Enter. Look at the resulting fraction or decimal; it represents the probability of selecting a blue bead. Then match that value to the corresponding answer choice.
Step-by-step Explanation
Translate probability into a fraction
For this type of problem, probability = (number of favorable outcomes) / (total number of possible outcomes).
Here, a favorable outcome means “picking a blue bead.” The total outcomes are all beads in the jar.
Find the total number of beads
Add up all the beads in the jar:
So there are 50 beads in total.
Find the number of favorable outcomes
We want the bead to be blue. The problem states there are 15 blue beads.
So the number of favorable outcomes is 15.
Write the probability as a fraction
Use the formula:
So the correct answer is , which matches choice C.