Calculate probability of selecting coloured counters from a bag.
", "licence": "None specified"}, "statement": "A bag contains:
$\\var{srn}$ small, red tokens,
$\\var{sbn}$ small, blue tokens,
$\\var{brn}$ large, red tokens, and
$\\var{bbn}$ large, blue tokens.
A probability is a fraction. You can give your answer as a fraction, decimal or percentage as these are all equivalent.
The formula for probability is:
\\[ P(A) = \\frac{\\text{number of possibilities for A}}{\\text{number of total possible outcomes}} \\]
\nFor this question the total possible outcomes are $\\var{srn}+\\var{sbn}+\\var{brn}+\\var{bbn} = \\var{total}$.
Therefore
\\[ P(\\text{A large red token}) = \\frac{\\var{brn}}{\\var{total}} = \\var[fractionnumbers]{brn/total}\\]
\nFor this question we need to know the total number of small tokens, i.e. $\\var{srn}+\\var{sbn} = \\var{srn+sbn}$.
Therefore
\\[ P(\\text{A small token}) = \\frac{\\var{srn+sbn}}{\\var{total}} = \\var[fractionnumbers]{(srn+sbn)/total}\\]
\n\nUse this link to find some resources which will help you revise this topic.
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What is the probability that it is a large, red token?
Give your answer as a fraction, or a decimal correct to 2dp.
You take a token at random.
What is the probability that it is a small token?
Give your answer as a fraction, or a decimal correct to 2dp.