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1 of 8 0-day streak

Use two-step probability trees

DIFFICULTYintrostandard
QUESTION TYPEMix of allChange
independent: red then redindependent: red then blueindependent: blue then redindependent: blue then blueindependent: both colours are the sameindependent: the colours are differentindependent: at least one colour is redindependent: the second colour is redNOWMix of allRecommended
Question 1 of 8

No calculator

Two spinners have equal-sized sectors. The first has 3 red sectors and 2 blue sectors. The second has 2 red sectors and 4 blue sectors. Spin them independently and record the colours in order

R means red and B means blue. Each branch shows the probability at that stage, given the earlier result. Complete the missing branch marked ?

Two-stage probability tree. R means red and B means blue. First branches: R 3/5, B ?. After R: R 1/3, B 2/3. After B: R 1/3, B 2/3.FirstSecondR3/5R1/3RRB2/3RBB?R1/3BRB2/3BB

Event \(E\): the second colour is red

(a)1 mark

Find the missing branch probability

Format: exact fraction or terminating decimal
(b)1 mark

Find the probability of blue then red

Format: exact fraction or terminating decimal
(c)2 marks

Find the probability of E

Format: exact fraction or terminating decimal