SAT Math 1.5 Statistics and Probability

SAT Math 1.5 Statistics and Probability. If Silas draws one card, then places it in his pocket and draws another, what is the probability that both cards will be blue?

Data AnalysisElementary Probability
LanguageEnglish Language
MathStatistics and Probability
Mathematics and Statistics AssessmentProbabilistic Reasoning
ProbabilityProbability
Problem Solving and Data AnalysisPercentages
Product TypeSAT Math
SAT MathStatistics and Probability
Statistics and ProbabilityProbability
Use rules of probability to compute probabilities of compound events

Transcript

00:20

what is the probability that both cards will be blue?

00:25

Round to the nearest tenth of a percent. And here are the potential answers…

00:30

Remember that the probability of a single trial is:

00:34

favorable divided by number of possible outcomes.

00:38

In the first trial, out of 12 cards, there are 3 blue cards.

00:42

There are 3 favorable outcomes, and 12 possible. This comes out to 3/12 or 1/4, or 25% chance.

00:49

Next, if we picked a blue card the first time, there would be 2 blue cards left in the deck,

00:54

and only 11 in total...

00:56

…which comes out to about 18%. To find the combined probability, we simply

01:01

multiply the two probabilities together.

01:04

.25 times .18 is .045…or 4.5%.

01:10

So our answer is (A).