Year 11 maths · C.1 · Probability
Probability of a single event
Probability = favourable outcomes ÷ all outcomes.
See worked examples
A bag holds 2 red, 3 blue, 6 green and 6 yellow marbles. One is picked without looking. What is the probability it is green? Write a fraction in lowest terms.
Answer: 6/17
A bag holds 8 red, 1 blue, 8 green and 1 yellow marbles. One is picked without looking. What is the probability it is yellow? Write a fraction in lowest terms.
Answer: 1/18
A bag holds 9 red, 8 blue, 9 green and 8 yellow marbles. One is picked without looking. What is the probability it is red? Write a fraction in lowest terms.
Answer: 9/34
Tip: Probability = favourable outcomes ÷ all outcomes.
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