This year, 40 students have each travelled by one or more of plane $$$(P)$$$, train $$$(T)$$$ or boat $$$(B)$$$. 7 have travelled only by plane. 11 have travelled only by train. 9 have travelled only by boat. $$\[ \begin{aligned} &\mathrm{n}(P \cap T)=8 \\ &\mathrm{n}(B \cap T)=3 \\ &\mathrm{n}(B \cap P)=6 \end{aligned} \]$$ Two students are chosen at random. Calculate the probability that they both have travelled only by plane. .............................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：0580_m20_qp_42 Year：2020 Question No：9(d)

Answer:

$\frac{7}{260}$ oe

Knowledge points:

E8.5 Calculate the probability of simple combined events, using possibility diagrams, tree diagrams and Venn diagrams. (In possibility diagrams, outcomes will be represented by points on a grid, and in tree diagrams, outcomes will be written at the end of branches and probabilities by the side of the branches.)

Answer:

Knowledge points:

Solution:

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