SAT · Problem Solving & Data Analysis · Scatterplots, tables, and probability
Question sat-q-00155
Easy Multiple choice Calculator OK
The question
A bag contains 2 red marbles and 4 blue marbles. If one marble is drawn at random, what is the probability that it is red?
- 4/2
- 2/4
- 4/6
- 2/6
Show answer & worked solution
Answer: 2/6
Worked solution. Probability = favorable outcomes / total outcomes = 2 / 6.
Why each wrong choice is wrong. Common distractors compute the probability of the other color, or use the wrong color count in the numerator or denominator.
Test-day tactic. Probability is favorable over total. Total includes everything in the sample space, not just the unfavorable outcomes.
About this question type
Items ask you to read a value off a scatterplot, to identify the line of best fit, to compute a probability or conditional probability from a two-way table, or to interpret a relative-frequency statement.
You will see a question shaped like this one on roughly every other official SAT form, typically at an early position in the section, where missing them carries an outsize penalty because the curve assumes everyone in your band gets them right. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.