Probability & Statistics 1 — Variant 2
A Level Mathematics · 9709/52 · Feb/March 2021
Questions
4 of 7 questions shown here, checked against the paper. The others are in the PDF above — they contain diagrams or maths we could not yet verify, and we would rather show you the original than a transcription we are not sure of.
1
A fair spinner with sides numbered is spun repeatedly. The score on each spin is the number on the side on which the spinner lands.
1(a)
[1]
Find the probability that a score of is obtained for the first time on the th spin.
1(b)
[2]
Find the probability that fewer than spins are required to obtain a score of for the first time.
2
Georgie has a red scarf, a blue scarf and a yellow scarf. Each day she wears exactly one of these scarves. The probabilities for the three colours are , and respectively. When she wears a red scarf, she always wears a hat. When she wears a blue scarf, she wears a hat with probability . When she wears a yellow scarf, she wears a hat with probability .
2(a)
[2]
Find the probability that on a randomly chosen day Georgie wears a hat.
2(b)
[3]
Find the probability that on a randomly chosen day Georgie wears a yellow scarf given that she does not wear a hat.
4
The random variable takes the values only. The probability that takes the value is , where is a constant.
4(a)
[2]
Draw up the probability distribution table for , in terms of .
4(b)
[4]
Show that .
6
6(a)
[2]
Find the total number of different arrangements of the letters in the word CATERPILLAR.
6(b)
[4]
Find the total number of different arrangements of the letters in the word CATERPILLAR in which there is an R at the beginning and an R at the end, and the two As are not together.
6(c)
[4]
Find the total number of different selections of letters from the letters of the word CATERPILLAR that contain both Rs and at least one A and at least one L.
Published by Cambridge Assessment International Education. Reproduced for study use.