All SAT Math Resources
Example Questions
Example Question #272 : Data Analysis
On the spinner shown in the figure above, what is the probability of spinning an A, B, or C?
None of the given answers.
The probability of spinning an A is . The probability of spinning an B is also , and the same goes for spinning a C.
To find the probability of spinning an A, B, or C, we simply add these individual probabilities together.
Example Question #112 : How To Find The Probability Of An Outcome
Robert pulls the queen of hearts out of a deck of standard playing cards. He does not replace the card. Next, Rebecca pulls out a card of her own from the same deck. What is the probability that Rebecca's card is also a queen?
None of the given answers.
Remember that we can find the probability of an event by dividing the number of possible desired outcomes by the total number of possible outcomes.
Since Robert has already pulled out the queen of hearts, that means that there are 51 cards remaining in the deck. That also means that there are only 3 queens left.
With this in mind, Rebecca pulls out a card from a deck of 51 total cards (the total number of possible outcomes), 3 of which are queens (the desired number of outcomes).
Therefore, the probability of her pulling out a queen is .
Example Question #3202 : Sat Mathematics
Joshua rolls a standard six-sided die and rolls a six. He rolls the same die a second time. What is the possibility that he rolls a six again?
The probability of an event is given by dividing the number of desired outcomes by the number of total outcomes.
Because each roll is an independent event, that means that the probability of rolling a second six is the same as rolling the first six.
The probability of rolling a six (one desired outcome) on a standard die (six total possible outcomes) is .
Example Question #113 : Probability
There are two events, and .
If and , then what is ?
Given two events, the following rule is true:
Therefore,
Example Question #3204 : Sat Mathematics
In a jar, I have 5 red marbles, 6 blue marbles, and 4 green marbles. What is the probability that I will choose blue and red out of two picks?
In a jar, there have 5 red marbles, 6 blue marbles, and 4 green marbles. What is the probability that I will choose blue and red out of two picks?
Step 1: Find the probability of getting only one color. We will denote probability of red as , probability of blue as and green as .
.
This fraction cannot be simplified anymore. The numerator is divisible by 2 and the denominator is not divisible by 2.
Step 2: We need to find the probability of getting 1 red and 1 blue. We need to use a formula: , where and .
Step 3: Using the formula in step 2, substitute and into the equation and multiply.
We get:
So, the probability of getting a red and a blue marble is .
Example Question #3201 : Sat Mathematics
Khalil has a spinner and a six-sided die. The spinner is divided into five equal sections. The five sections are labeled Red, Green, Blue, Yellow, and Purple, individually. Each side of the die corresponds to a number one through six.
What is the probability of Khalil spinning a primary color and rolling an odd number?
None of the given answers.
Remember that the probability of an event is given by dividing the number of desired outcomes by the number of total outcomes.
The probability of Khalil spinning one of the three primary colors (Red, Blue, or Yellow) is .
The probability of Khalil rolling an odd number (1, 3, or 5) is .
We want to know the probability of Khalil spinning a primary color AND rolling an odd number. To do this compound probability, we multiply the two probabilities together.
Example Question #121 : Probability
The figure above showers a spinner divided into four equal sections.
If Raul spins the spinner, what is the probability that he does NOT spin an A?
None of the given answers are correct.
The probability of an event is given by dividing the number of desired outcomes by the number of total outcomes.
In this case, we want to find all the possibilities of Raul spinning anything but an A. That means, he can spin a B, C, or D.
Therefore, there are three desired outcomes out of a total four possible outcomes.
This means that the probability of Raul not spinning an A is .
Example Question #282 : Data Analysis
Mike is doing a magic trick where two people pull cards without putting them back in the deck. Sam pulls out the Ace of Spades, and Adam pulls out the Queen of Hearts. If Kristi pulls one card, what is the probability that she pulls out an Ace?
If Adam and Sam have already pulled out one card a piece and not put them back in the deck, that means that there are cards left.
We also know that one of the Aces has already been pulled. Since there are four Aces in a deck, that means that there are left.
We know that the probability of an event is the number of desired outcomes divided by the total number of possible outcomes. Therefore, the probability of Kristi pulling an Ace is .
Example Question #122 : Probability
All the Hearts in a standard deck of playing cards are taken out. Kristen draws one card. What is the probability that she draws a Queen?
A standard deck of cards has cards in it, and it is divided equally into four suits: Hearts, Spades, Clubs, and Diamonds. In this problem, all the Hearts are taken away before Kristen draws her card. That means that our deck has total cards in it.
Remember that the probability of an event occurring is expressed as the number of desired outcomes divided by the total number of possible outcomes. In our case, we want to know the probability that Kristen draws a Queen. In our modified deck, there are three Queens (one of Diamonds, Spades, and Clubs), so there are three outcomes that would give us our desired result.
Therefore, the probability that she draws a Queen is .
Example Question #123 : Probability
Yousef has a spinner that is divided into equal sections. Each section is assigned one specific color: Red, Blue, Green, Orange, and Yellow. Yousef also has two standard six-sided dice.
If he spins the spinner and rolls the two dices, what is the probability that he spins Blue and rolls two sixes?
None of the given answers.
Here, we have a compound probability problem. Remember that the probability of a single event is given by dividing the number of desired outcomes by the number of total outcomes.
With that in mind, the probability of Yousef's spinner landing on Blue is since there are section possible outcomes and one desired outcome.
For the first die, the probability of him rolling a six is . The same goes for the second die since the two rolls are independent of one another.
The probability of multiple events happening together can be expressed like this:
Therefore, the probability of Yousef spinning Blue and rolling two sixes is:
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