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6.08 Combinations and Probability

Interactive practice questions

A box contains 6 pens of different colours: red, green, blue, yellow, black and white. Two pens are drawn at random without replacement.

a

How many possible selections are there?

b

What is the probability of drawing the green and black pens?

Easy
2min

A newspaper editor is deciding which of $5$5 articles to print on the front page.

Easy
2min

A menu has three entrées ($E_1,E_2,E_3$E1,E2,E3), four mains ($M_1,M_2,M_3,M_4$M1,M2,M3,M4) and two desserts ($D_1,D_2$D1,D2). A meal is made up of one of each.

Easy
1min

A container contains twelve cards. The cards are marked with the numbers 1 to 12. From the container, five cards are drawn at random without replacement.

Easy
2min
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Outcomes

1.3.2

use the notation columnvector(nr) and the formula columnvector(nr)=n!r!(n−r)! for the number of combinations of r objects taken from a set of n distinct objects

1.3.13

understand the notion of a conditional probability and recognise and use language that indicates conditionality

1.3.14

use the notation 𝑃(𝐴|𝐵) and the formula 𝑃(𝐴∩𝐵) =𝑃(𝐴|𝐵)𝑃(𝐵)

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