Two-item selection from population

9 In a survey, 50 people were asked whether they had passed A-level English and whether they had passed A-level Mathematics. The numbers of people in various categories are shown in the Venn diagram.
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1. A person is chosen at random from the 50 people. Find the probability that this person has passed A-level Mathematics.
2. Two people are chosen at random, without replacement, from those who have passed A-level in at least one of the two subjects. Determine the probability that both of these people have passed A-level Mathematics.

4 There are four human blood groups; these are called \(\mathrm { O } , \mathrm { A } , \mathrm { B }\) and AB . Each person has one of these blood groups. The table below shows the distribution of blood groups in a large country. Two people are selected at random from this country.

1. Find the probability that at least one of these two people has blood group O .
2. Find the probability that each of these two people has a different blood group.

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1. Bag A contains 7 blue discs, 4 red discs and 1 yellow disc. Two discs are drawn at random from bag A without replacement.
   Find the probability that exactly one of the discs is blue.
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2. Bag A contains 7 blue discs, 4 red discs and 1 yellow disc.