Handling Data 4
2 marks · NormalA bag contains 120 marbles. 50 are red, 38 are blue and the rest are green. A marble is chosen at random. Calculate the probability that it is green. Give your answer as a fraction and as a decimal to 2 decimal places.
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32/120 or 0.27 (±0.01)
Also accept: 8/30; 0.266; 0.267
Common mistakes: Forgetting to subtract blue and red from total
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Marking points
M1 · 1 mark · Calculates number of green marbles: 120 − 50 − 38 = 32.
A1 · 1 mark · Probability given as 32/120 and correct decimal as 0.27 (accept up to 0.27 with correct rounding).
Worked solution
Number of green marbles = 120 - 50 - 38 = 32