9709/53 · May/June 2026
Download PDFA fair 8-sided dice with faces labelled 1, 2, 3, 4, 5, 6, 7, 8 is thrown repeatedly.
Find the probability that a 5 will be obtained for the first time on the 7th throw.
Find the probability that a 5 will be obtained for the first time before the 10th throw.
Find the probability that a 5 will be obtained at least once but no more than three times in 12 randomly chosen throws.
The random variable takes the values . It is given that , where is a constant.
Draw up the probability distribution table for , giving the probabilities as numerical fractions not involving .
Find the value of .
The times taken, in minutes, by 150 students to complete a particular computer game are summarised in the table.
| frequency |
Draw a histogram to represent this information.
Calculate an estimate for the mean of these times.
In which class interval does the 40th percentile of the times lie?
Ebere has a coin which is biased so that the probability of obtaining a head is . She also has two bags containing coloured discs. Bag contains 5 red discs and 3 blue discs. Bag contains 4 red discs and 5 green discs. Ebere tosses her coin. If she obtains a head, she chooses two discs from bag , at random, one at a time and without replacement. If she obtains a tail, she chooses two discs from bag , at random, one at a time and without replacement.
Draw a fully labelled tree diagram to represent this information.
Find the probability that Ebere obtains two discs of the same colour.
Find the probability that Ebere obtained a head with her coin given that at least one of the discs is red.
The lengths of Indian cobra snakes are normally distributed with mean and standard deviation . Find the probability that a randomly chosen Indian cobra has a length between and .
The masses of Indian cobras are normally distributed with mean and standard deviation . It is known that of Indian cobras have a mass less than . Find the value of .
A random sample of 80 Indian cobras is taken. Use an approximation to find the probability that fewer than 60 of these 80 Indian cobras have a mass less than .
Find the number of different arrangements of the 10 letters in the word POSSESSION in which the four Ss are all next to each other and the two Os are not next to each other.
Find the number of different arrangements of the 10 letters in the word POSSESSION in which the P is at the beginning, the N is at the end and there are exactly four letters between the two Os.
Five letters are selected from the 10 letters in the word POSSESSION. Find the number of different selections in which the five letters include at least two Ss and at least one O.






