How to Solve Probability Problems
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The Solution for Probability Problems
It is possible to solve a lot of easy probability problems merely by understanding \(2\) basic rules, which are:
- The possibility of any sample point could be in a range of \(0\) to \(1\).
- The total probabilities of all the sample points within a sample space equals \(1\).
Probability of Sample Points
The possibility of a sample point happening is a measure of the possibility sample point will happen.
Example One
Why don’t we do a basic statistical experiment? We’ll flip a coin once. This coin flip could have \(1\) or \(2\) equally-possible outcomes – tails or heads. Together, those results represent the sample space of this experiment. Independently, each of the outcomes stands for a sample point within the sample space. What’s the chances for each sample point?
Solution:
The total of the chances for every sample point has to be \(1\). Plus the chances of acquiring a head is the same as the chances of getting a tail. So, the chances for each sample point (tails or heads) has to be \(\frac{1}{2}\).
Chances for an Event
The chance for an event is a measure of the possibility it will happen. By agreement, statisticians have formed these rules.
- The chances for an event can be in the range of zero to \(1\).
- The chances of event \(A\) is the total of the chances of all the sample points for event \(A\).
- The chance of event \(A\) is shown via \(P(A)\).
So, if event \(A\) weren’t likely to happen, then \(P(A)\) is going to be close to zero. So if event A were quite likely to happen, \(P(A)\) would be near \(1\).
Example two
Let’s pull a card from a deck of poker cards. What’s the chances we’ll get a spade?
Solution:
The sample space for this experiment comprises fifty-two cards, so the chances for each sample point is \(\frac{1}{52}\) . Because there are thirteen spades in a deck, the chances of pulling out a spade is:
\(P(Spade) \ = \ 13 \times \frac{1}{52} \ = \ \frac{1}{4}\)
Conclusion
- Probability is the chance of a future event. It’s shown as a number in-between zero (could not ever happen) to \(1\) (this is going to happen all the time).
- Probability can be shown using fractions, decimals, or percentages.
- To find a solution to a probability problem ascertain the event, and figure out the amount of outcomes for the event, you should utilize probability law: \(\frac{number \ of \ favorable outcomes}{total \ number \ of \ possible \ outcomes}\)
Free printable Worksheets
Exercises for Probability Problems
1) A number is chosen at random from \( 1 \) to \( 23 \). Find the probability of selecting a \( 2 \) or smaller.
2) A number is chosen at random from \( 1 \) to \( 16 \). Find the probability of selecting prime numbers.
3) A number is chosen at random from \( 1 \) to \( 46 \). Find the probability of selecting prime numbers.
4) Bag A contains \( 9 \) red marbles and \( 5 \) green marbles. Bag B contains \( 3 \) black marbles and \( 8 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?
5) Bag A contains \( 23 \) red marbles and \( 5 \) green marbles. Bag B contains \( 1 \) black marbles and \( 9 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?
6) Bag A contains \( 16 \) red marbles and \( 7 \) green marbles. Bag B contains \( 8 \) black marbles and \( 2 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?
7) Bag A contains \( 17 \) red marbles and \( 9 \) green marbles. Bag B contains \( 7 \) black marbles and \( 6 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?
8) Bag A contains \( 24 \) red marbles and \( 7 \) green marbles. Bag B contains \( 5 \) black marbles and \( 9 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?
9) A number is chosen at random from \( 1 \) to \( 32 \). Find the probability of selecting prime numbers.
10) A number is chosen at random from \( 1 \) to \( 18 \). Find the probability of selecting prime numbers.
1) A number is chosen at random from \( 1 \) to \( 23 \). Find the probability of selecting a \( 2 \) or smaller. \( \ \color{red}{\frac{2}{23}} \)
2) A number is chosen at random from \( 1 \) to \( 16 \). Find the probability of selecting prime numbers. \( \ \color{red}{\frac{3}{8}} \)
3) A number is chosen at random from \( 1 \) to \( 46 \). Find the probability of selecting prime numbers. \( \ \color{red}{\frac{7}{23}} \)
4) Bag A contains \( 9 \) red marbles and \( 5 \) green marbles. Bag B contains \( 3 \) black marbles and \( 8 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?\( \ \color{red}{\frac{5}{14} \ , \frac{3}{11}} \)
5) Bag A contains \( 23 \) red marbles and \( 5 \) green marbles. Bag B contains \( 1 \) black marbles and \( 9 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?\( \ \color{red}{\frac{5}{28} \ , \frac{1}{10}} \)
6) Bag A contains \( 16 \) red marbles and \( 7 \) green marbles. Bag B contains \( 8 \) black marbles and \( 2 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?\( \ \color{red}{\frac{7}{23} \ , \frac{4}{5}} \)
7) Bag A contains \( 17 \) red marbles and \( 9 \) green marbles. Bag B contains \( 7 \) black marbles and \( 6 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?\( \ \color{red}{\frac{9}{26} \ , \frac{7}{13}} \)
8) Bag A contains \( 24 \) red marbles and \( 7 \) green marbles. Bag B contains \( 5 \) black marbles and \( 9 \) orange marbles. What is the probability of selecting a green marble at random from bag A? What is the probability of selecting a black marble at random from Bag B?\( \ \color{red}{\frac{7}{31} \ , \frac{5}{14}} \)
9) A number is chosen at random from \( 1 \) to \( 32 \). Find the probability of selecting prime numbers. \( \ \color{red}{\frac{11}{32}} \)
10) A number is chosen at random from \( 1 \) to \( 18 \). Find the probability of selecting prime numbers. \( \ \color{red}{\frac{7}{18}} \)
Probability Problems Quiz