Master Probability, Permutations, and Combinations on the GMAT

:chart_with_upwards_trend:Solve complex probability, permutations, and combinations questions by solving for what you don't want and subtracting it from the total.

:bulb:Look for clues in the question like 'at least' that indicate the use of the solve-for-what-you-don't-want strategy.

:game_die:Apply the solve-for-what-you-don't-want strategy to probability questions to find the probability of specific events.

:gift:Use the solve-for-what-you-don't-want strategy for permutations questions with difficult restrictions, such as not allowing all items to be the same color.

:triangular_ruler:Apply the solve-for-what-you-don't-want strategy to combinations questions, considering the restriction of not forming an equilateral triangle.

How can I solve complex probability questions on the GMAT?

—Use the solve-for-what-you-don't-want strategy by finding the probability of what you don't want and subtracting it from one.

When should I use the solve-for-what-you-don't-want strategy?

—Look for clues in the question, like 'at least,' that indicate the use of this strategy.

Can I use the solve-for-what-you-don't-want strategy for permutations questions?

—Yes, apply this strategy to find permutations that do not meet certain restrictions.

How can I solve combinations questions with difficult restrictions?

—Use the solve-for-what-you-don't-want strategy and consider the restriction when selecting combinations.

Are there any tips for using the solve-for-what-you-don't-want strategy effectively?

—Practice applying this strategy to different types of questions to improve your problem-solving skills.

00:05Introduction by Erica, who specializes in GMAT preparation and has a helpful tip for probability, permutations, and combinations questions.

00:25Probability, permutations, and combinations are important topics on the GMAT, regardless of the difficulty level of the test.

02:13Understanding the total probability and the hint provided by the phrase 'at least' in probability questions.

08:27Using the solve-for-what-you-don't-want strategy for permutations questions with restrictions, like not allowing all items to be the same color.

10:37Applying the solve-for-what-you-don't-want strategy to combinations questions, considering the restriction of not forming an equilateral triangle.