SAT · Problem Solving & Data Analysis · Scatterplots, tables, and probability
Question sat-q-00157
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The question
A bag contains 3 red marbles and 8 blue marbles. If one marble is drawn at random, what is the probability that it is red?
- 8/3
- 8/11
- 3/11
- 3/8
Show answer & worked solution
Answer: 3/11
Worked solution. Probability = favorable outcomes / total outcomes = 3 / 11.
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 a moderate position in the section — solidly within the range that separates a 600-band student from a 700-band student. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.