Probability-primary mathematics

Probability-primary mathematics

Probability

Probability is the likelihood or chance of an event occurring.

Many events can’t be predicted with total certainty. The best we can say is how likely they are to happen, using the idea of probability.

Tossing a Coin

When a coin is tossed, there are two possible outcomes:

  • heads (H) or
  • tails (T)

We say that the probability of the coin landing H is ½

And the probability of the coin landing T is ½

Throwing Dice 

When a single  die is thrown, there are six possible outcomes: 1, 2, 3, 4, 5, 6.

 

In general:

Example 1:

What is the chances of rolling a “4” with a die

Number of ways it can happen: 1 (there is only 1 face with a “4” on it)

Total number of outcomes: 6 (there are 6 faces altogether)

Example 2:

There are 5 pens in a bag: 4 are blue, and 1 is red.

What is the probability that a blue pen gets picked?

Number of ways it can happen: 4 (there are 4 blues)

Total number of outcomes: 5 (there are 5 marbles in total)

The probabilities lie between 0 and 1

(i) The probability of something which is certain to happen is 1. For example, the probability that the sun will rise from the east tomorrow is 1

(ii) The probability of something which is impossible to happen is 0. For example the probability that man has four eyes = 0

(iii) The probability of something not happening is 1 minus the probability that it will happen.

For revision questions and answers download  PDF

Probality- upper primary

Sponsored by The Science Foundation College + 256 753 80 27 09

Compiled by Dr. Bbosa Science +256 778 633 682

Please subscribe to receive up to date information

CATEGORIES
TAGS
Share This

COMMENTS

Wordpress (1)
  • comment-avatar

    Thanks As an average 25 seems to be as good as any other numberOne other factor to consider:- we probably have a smaller percentage of our 10th cousins living today than the percentage of 4th cousins Some (many?) of our 10th cousins were born many years ago, or haven’t yed been born, and so they will not have been tested A higher percentage of fourth cousinds will have done a DNA testIs there a measure of the spread of the ages for cousins?Dewi

  • Disqus ( )