Introduction to combinatorics and probability
counting objects by listing them, simple random experiments (a die, a polyhedral die, drawing a ball), probability of an event
Exercises are drawn at random from a large bank - every click gives a different set.
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What is the probability?
A 8-sided die with faces numbered 1 to 8 is rolled once. What is the probability that a multiple of 3 comes up?
What is the probability?
A coin is tossed once. What is the probability that tails comes up?
How many possibilities are there?
How many different two-digit numbers can be made from the digits 2, 5, 8 if digits cannot repeat?
What is the probability?
A single die is rolled. What is the probability that an even number comes up?
How many possibilities are there?
How many two-digit numbers have digits whose product is 24?
What is the probability?
A box contains 20 balls: yellow, blue and red. The probability of drawing a red ball is 1/5. One ball is drawn. What is the probability that the ball drawn is not red?
Problem
A box contains only white and black balls, including 7 white balls. One ball is drawn. The probability of drawing a white ball is 1/4. How many balls are in the box altogether?
How many possibilities are there?
Triangles with the same side lengths count as one. How many triangles have a perimeter of 24 m and sides whose lengths are whole numbers of metres?
What is the probability?
A box holds 2 white balls and 3 black balls. One ball is drawn. What is the probability of drawing a white ball?
What is the probability?
A 20-sided die with faces numbered 1 to 20 is rolled once. What is the probability that a two-digit number comes up?
This address is one particular set - everyone who opens it gets exactly the same exercises. Copy the link from the address bar and send it to the class. You can generate a new set at the top of the page.
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These exercises are part of it. On the board itself you can plot a function, write a formula in LaTeX, or solve a problem together with a teacher or a friend - live, in the browser. Our app is completely free.