Mathematics · May / June 2020 · Paper 42 · Question 7
0580
As printed in the paper
The question as text
Tanya plants some seeds. The probability that a seed will produce flowers is 0.8 . When a seed produces flowers, the probability that the flowers are red is 0.6 and the probability that the flowers are yellow is 0.3 .
Read automatically from the paper; the printed page above is exact.
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7(a)[1]
0.1 [1]
7(b)(i)[2]
0.2 oe 0.6, 0.3, 0.1 oe [2]
B1 for 0.2
B1 for 0.6, 0.3, 0.1
7(b)(ii)[2]
0.48 oe [2]
FT their 0.6 from tree diagram
M1 for 0.8 × their 0.6
7(b)(iii)[3]
0.28 oe [3]
M2 for 0.2 + 0.8 × 0.1 oe
or M1 for 0.2 or 0.8 × 0.1 or 0.8 × (0.6 + 0.3)
7(c)[3]
0.32 oe [3]
M2 for 0.8 × 0.2 + 0.2 × 0.8 oe
M1 for one of these products
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