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Secondary 2 Mathematics Statistics Probability Quiz
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Questions
Secondary 2 Mathematics Quiz - Statistics Probability
Name: ___________________________
Class: ___________________________
Date: ___________________________
Score: ________ / 50
Duration: 60 minutes
Total Marks: 50
Instructions
- Answer all questions in the spaces provided.
- Show all working clearly. Marks are awarded for correct method as well as final answers.
- The number of marks for each question is shown in brackets, e.g. [2].
- Do not use a calculator unless stated.
- Write your answers in the blank spaces or on the dotted lines.
Section A: Data Handling and Representation (Questions 1–5)
Questions 1–5 test your ability to read, interpret, and construct statistical diagrams.
1. The bar chart below shows the number of books read by five students in a month.
| Student | Aisha | Ben | Clara | Dan | Ella |
|---|---|---|---|---|---|
| Books read | 8 | 12 | 6 | 10 | 14 |
(a) Who read the most books? [1]
(b) What is the total number of books read by all five students? [1]
(c) What is the mean number of books read per student? [2]
2. A group of 20 students were asked how many hours they spent on homework last Saturday. The results are shown below.
3, 2, 4, 1, 3, 5, 2, 3, 4, 2,
1, 3, 3, 4, 2, 5, 3, 2, 4, 3
(a) Complete the frequency table below.
| Hours | Tally | Frequency |
|---|---|---|
| 1 | ||
| 2 | ||
| 3 | ||
| 4 | ||
| 5 |
[2]
(b) What is the mode of the data? [1]
(c) What is the median of the data? [2]
3. The pie chart below represents the favourite sports of 180 students in a school.
| Sport | Angle (°) |
|---|---|
| Football | 120 |
| Basketball | 90 |
| Swimming | 60 |
| Badminton | 50 |
| Volleyball | 40 |
(a) Verify that the angles sum to 360°. Show your working. [1]
(b) How many students chose Football as their favourite sport? [2]
(c) How many students chose Swimming? [1]
(d) What fraction of the students chose Badminton? Give your answer in its simplest form. [2]
4. The stem-and-leaf diagram below shows the heights (in cm) of 15 Secondary 2 students.
15 | 2 4 6 8
16 | 0 1 3 5 7 9
17 | 2 4 6
18 | 1
Key: 15 | 2 means 152 cm
(a) What is the height of the shortest student? [1]
(b) What is the height of the tallest student? [1]
(c) Find the median height. [2]
(d) Find the range of the heights. [1]
5. The line graph below shows the temperature (°C) recorded at noon over five consecutive days.
| Day | Mon | Tue | Wed | Thu | Fri |
|---|---|---|---|---|---|
| Temperature (°C) | 31 | 33 | 30 | 34 | 32 |
(a) What was the temperature on Wednesday? [1]
(b) What was the mean noon temperature over the five days? [2]
(c) On which day was the temperature the highest? [1]
(d) Find the difference between the highest and lowest temperatures. [1]
Section B: Statistical Measures (Questions 6–10)
Questions 6–10 test your ability to calculate and interpret mean, median, mode, and range.
6. The ages (in years) of seven members of a family are:
12, 8, 35, 38, 10, 6, 65
(a) Find the mean age. [2]
(b) Find the median age. [2]
(c) Find the range of the ages. [1]
(d) Explain why the median is a more representative measure of central tendency than the mean for this data set. [2]
7. The test marks of 10 students are given below.
68, 72, 75, 75, 80, 82, 85, 85, 85, 90
(a) Calculate the mean mark. [2]
(b) State the mode. [1]
(c) Find the median mark. [2]
(d) A new student joins the class and scores 45. Without recalculating, explain how this affects the mean. [1]
8. The table below shows the number of goals scored by a football team in 12 matches.
| Goals scored | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| Frequency | 2 | 3 | 4 | 2 | 1 |
(a) Calculate the mean number of goals per match. [3]
(b) What is the modal number of goals? [1]
(c) Find the median number of goals. [2]
9. The mean of five numbers is 20. Four of the numbers are 15, 18, 24, and 23.
(a) Find the fifth number. [2]
(b) If each of the five numbers is increased by 3, what is the new mean? [1]
(c) If each of the original five numbers is doubled, what is the new mean? [1]
10. The mean height of 8 students is 155 cm. When a new student joins the group, the mean height becomes 157 cm.
(a) Find the total height of the original 8 students. [1]
(b) Find the total height of all 9 students. [1]
(c) Find the height of the new student. [2]
Section C: Probability (Questions 11–15)
Questions 11–15 test your understanding of basic probability concepts.
11. A fair six-sided die is rolled once.
(a) What is the probability of rolling a 4? [1]
(b) What is the probability of rolling an even number? [2]
(c) What is the probability of rolling a number greater than 6? [1]
(d) What is the probability of rolling a number less than 7? [1]
12. A bag contains 5 red marbles, 3 blue marbles, and 2 green marbles. One marble is picked at random.
(a) What is the probability of picking a red marble? [1]
(b) What is the probability of picking a blue marble? [1]
(c) What is the probability of picking a yellow marble? [1]
(d) What is the probability of picking either a red or a green marble? [2]
(e) Which colour is most likely to be picked? Explain your answer. [1]
13. A letter is chosen at random from the word PROBABILITY.
(a) How many letters are there in total? [1]
(b) What is the probability that the letter chosen is a vowel? [2]
(c) What is the probability that the letter chosen is B? [2]
(d) What is the probability that the letter chosen is not B? [1]
14. A spinner has 8 equal sectors numbered 1 to 8.
(a) What is the probability of landing on a prime number? [2]
(b) What is the probability of landing on a multiple of 3? [2]
(c) What is the probability of landing on a number that is both prime and a multiple of 3? [1]
(d) Are the events "landing on a prime number" and "landing on a multiple of 3" mutually exclusive? Explain. [2]
15. Two fair coins are tossed.
(a) List all the possible outcomes. [2]
(b) What is the probability of getting two heads? [1]
(c) What is the probability of getting exactly one head? [1]
(d) What is the probability of getting at least one head? [2]
Section D: Combined Statistics and Probability (Questions 16–20)
Questions 16–20 combine statistical reasoning with probability in context.
16. The table below shows the results when a biased six-sided die was rolled 60 times.
| Score | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| Frequency | 8 | 10 | 12 | 15 | 9 | 6 |
(a) Which score appeared most often? [1]
(b) Estimate the probability of rolling a 4 with this biased die. [2]
(c) Estimate the probability of rolling an odd number. [2]
(d) If the die is rolled 300 times, approximately how many times would you expect to roll a 6? [2]
17. In a class of 30 students, 18 students like Mathematics, 15 students like Science, and 5 students like neither subject.
(a) How many students like both Mathematics and Science? [3]
(b) A student is chosen at random. What is the probability that the student likes Mathematics only? [2]
(c) What is the probability that the student likes at least one of the two subjects? [2]
18. The grouped frequency table below shows the time (in minutes) taken by 40 students to complete a quiz.
| Time (min) | 5 – 9 | 10 – 14 | 15 – 19 | 20 – 24 | 25 – 29 |
|---|---|---|---|---|---|
| Frequency | 6 | 12 | 10 | 8 | 4 |
(a) Which is the modal class? [1]
(b) Estimate the mean time taken. Use the midpoint of each class. [4]
(c) A student is chosen at random. Estimate the probability that the student took 20 minutes or more. [2]
19. A bag contains red, blue, and yellow counters. The probability of picking a red counter is 0.4 and the probability of picking a blue counter is 0.35.
(a) Find the probability of picking a yellow counter. [2]
(b) If there are 80 counters in the bag, how many red counters are there? [2]
(c) If there are 80 counters in the bag, how many yellow counters are there? [2]
(d) A counter is picked at random and not replaced. A second counter is then picked. Explain why the probability of the second pick is different from the first. [2]
20. The dual bar chart below shows the number of points scored by Team A and Team B in six basketball games.
| Game | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| Team A | 45 | 52 | 38 | 60 | 48 | 55 |
| Team B | 42 | 50 | 44 | 58 | 50 | 46 |
(a) Find the mean number of points scored by Team A. [2]
(b) Find the mean number of points scored by Team B. [2]
(c) Find the range of points for Team A. [1]
(d) Find the range of points for Team B. [1]
(e) Based on the means and ranges, which team performed more consistently? Explain your answer. [2]
End of Quiz
Answers
Secondary 2 Mathematics Quiz - Statistics Probability
Answer Key
Question 1
(a) Ella [1]
(b) 8 + 12 + 6 + 10 + 14 = 50 books [1]
(c) Mean = 50 ÷ 5 = 10 books [2]
Marking: Award [1] for correct sum, [1] for correct division and answer.
Question 2
(a)
| Hours | Tally | Frequency |
|---|---|---|
| 1 | II | 2 |
| 2 | IIII | 5 |
| 3 | IIII I | 6 |
| 4 | IIII | 4 |
| 5 | II | 3 |
[2] — Award [1] for each correct row (any 4 out of 5 correct rows for [1]).
(b) Mode = 3 (occurs most frequently, 6 times) [1]
(c) Arrange in order: 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5
There are 20 values. Median = average of 10th and 11th values = (3 + 3) ÷ 2 = 3 [2]
Marking: Award [1] for correct ordering or identifying positions, [1] for correct answer.
Question 3
(a) 120 + 90 + 60 + 50 + 40 = 360° ✓ [1]
(b) Football: (120/360) × 180 = 60 students [2]
Marking: Award [1] for correct fraction, [1] for correct answer.
(c) Swimming: (60/360) × 180 = 30 students [1]
(d) Badminton: 50/360 = 5/36 [2]
Marking: Award [1] for correct fraction, [1] for simplification.
Question 4
(a) Shortest: 152 cm [1]
(b) Tallest: 181 cm [1]
(c) There are 15 values. The median is the 8th value.
Values in order: 152, 154, 156, 158, 160, 161, 163, 165, 167, 169, 172, 174, 176, 181
Median = 165 cm [2]
Marking: Award [1] for identifying the 8th position, [1] for correct value.
(d) Range = 181 − 152 = 29 cm [1]
Question 5
(a) 30°C [1]
(b) Mean = (31 + 33 + 30 + 34 + 32) ÷ 5 = 160 ÷ 5 = 32°C [2]
Marking: Award [1] for correct sum, [1] for correct division.
(c) Thursday [1]
(d) Highest = 34, Lowest = 30. Difference = 34 − 30 = 4°C [1]
Question 6
(a) Mean = (12 + 8 + 35 + 38 + 10 + 6 + 65) ÷ 7 = 174 ÷ 7 = 24.9 years (or 24 6/7) [2]
Marking: Award [1] for correct sum, [1] for correct division.
(b) Arrange in order: 6, 8, 10, 12, 35, 38, 65
Median (4th value) = 12 years [2]
Marking: Award [1] for correct ordering, [1] for correct median.
(c) Range = 65 − 6 = 59 years [1]
(d) The data contains extreme values (65, 38, 35) which are much higher than most values. These outliers pull the mean upward, making it unrepresentative of the "typical" age. The median (12) is not affected by extreme values and better represents the centre of the data. [2]
Marking: Award [1] for identifying outliers/extreme values, [1] for explaining that median is not affected by them.
Question 7
(a) Mean = (68 + 72 + 75 + 75 + 80 + 82 + 85 + 85 + 85 + 90) ÷ 10 = 797 ÷ 10 = 79.7 [2]
Marking: Award [1] for correct sum, [1] for correct division.
(b) Mode = 85 (occurs 3 times) [1]
(c) There are 10 values. Median = average of 5th and 6th values = (80 + 82) ÷ 2 = 81 [2]
Marking: Award [1] for identifying 5th and 6th values, [1] for correct calculation.
(d) The mean will decrease because 45 is less than the current mean of 79.7, so adding a value below the mean pulls the average down. [1]
Question 8
(a) Mean = (0×2 + 1×3 + 2×4 + 3×2 + 4×1) ÷ 12 = (0 + 3 + 8 + 6 + 4) ÷ 12 = 21 ÷ 12 = 1.75 goals [3]
Marking: Award [1] for correct multiplication, [1] for correct sum, [1] for correct division.
(b) Mode = 2 (frequency 4, the highest) [1]
(c) There are 12 values. List: 0, 0, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4
Median = average of 6th and 7th values = (2 + 2) ÷ 2 = 2 [2]
Marking: Award [1] for correct ordering or identification, [1] for correct answer.
Question 9
(a) Total of five numbers = 20 × 5 = 100
Sum of four numbers = 15 + 18 + 24 + 23 = 80
Fifth number = 100 − 80 = 20 [2]
Marking: Award [1] for finding total, [1] for correct subtraction.
(b) New mean = 20 + 3 = 23 [1]
Adding a constant to every value shifts the mean by that constant.
(c) New mean = 20 × 2 = 40 [1]
Multiplying every value by a constant multiplies the mean by that constant.
Question 10
(a) Total height of 8 students = 8 × 155 = 1240 cm [1]
(b) Total height of 9 students = 9 × 157 = 1413 cm [1]
(c) Height of new student = 1413 − 1240 = 173 cm [2]
Marking: Award [1] for correct subtraction, [1] for correct answer with units.
Question 11
(a) P(4) = 1/6 [1]
(b) Even numbers: 2, 4, 6 → P(even) = 3/6 = 1/2 [2]
Marking: Award [1] for identifying 3 even numbers, [1] for correct probability.
(c) P(>6) = 0 (no face shows a number greater than 6) [1]
(d) P(<7) = 6/6 = 1 (all outcomes are less than 7; this is a certain event) [1]
Question 12
Total marbles = 5 + 3 + 2 = 10
(a) P(red) = 5/10 = 1/2 [1]
(b) P(blue) = 3/10 [1]
(c) P(yellow) = 0/10 = 0 (there are no yellow marbles) [1]
(d) P(red or green) = (5 + 2)/10 = 7/10 [2]
Marking: Award [1] for adding frequencies, [1] for correct probability.
(e) Red is most likely because it has the highest number of marbles (5 out of 10), giving the greatest probability. [1]
Question 13
The word PROBABILITY has 11 letters: P, R, O, B, A, B, I, L, I, T, Y
(a) 11 letters [1]
(b) Vowels: O, A, I, I → 4 vowels. P(vowel) = 4/11 [2]
Marking: Award [1] for identifying 4 vowels, [1] for correct probability.
(c) B appears 2 times. P(B) = 2/11 [2]
Marking: Award [1] for identifying 2 B's, [1] for correct probability.
(d) P(not B) = 1 − 2/11 = 9/11 [1]
Question 14
Numbers: 1, 2, 3, 4, 5, 6, 7, 8
(a) Prime numbers: 2, 3, 5, 7 → 4 primes. P(prime) = 4/8 = 1/2 [2]
Marking: Award [1] for identifying 4 primes, [1] for correct probability.
(b) Multiples of 3: 3, 6 → 2 values. P(multiple of 3) = 2/8 = 1/4 [2]
Marking: Award [1] for identifying multiples of 3, [1] for correct probability.
(c) The only number that is both prime and a multiple of 3 is 3. P = 1/8 [1]
(d) No, the events are not mutually exclusive because the number 3 is both prime and a multiple of 3. Since P(prime AND multiple of 3) = 1/8 ≠ 0, the events can occur together. [2]
Marking: Award [1] for correct conclusion, [1] for valid explanation.
Question 15
(a) Possible outcomes: HH, HT, TH, TT [2]
Marking: Award [2] for all 4 correct, [1] for any 2–3 correct.
(b) P(two heads) = P(HH) = 1/4 [1]
(c) P(exactly one head) = P(HT or TH) = 2/4 = 1/2 [1]
(d) P(at least one head) = P(HH, HT, or TH) = 3/4 [2]
Marking: Award [1] for identifying 3 favourable outcomes, [1] for correct probability.
Question 16
(a) Score 4 appeared most often (frequency 15) [1]
(b) P(4) ≈ 15/60 = 1/4 [2]
Marking: Award [1] for correct fraction, [1] for simplification.
(c) Odd numbers: 1, 3, 5. Frequency = 8 + 12 + 9 = 29
P(odd) ≈ 29/60 = 29/60 [2]
Marking: Award [1] for correct sum of frequencies, [1] for correct probability.
(d) Expected frequency of 6 = (6/60) × 300 = 30 times [2]
Marking: Award [1] for correct proportion, [1] for correct answer.
Question 17
Let M = Mathematics, S = Science.
n(M) = 18, n(S) = 15, n(neither) = 5, Total = 30
(a) n(at least one) = 30 − 5 = 25
n(M ∪ S) = n(M) + n(S) − n(M ∩ S)
25 = 18 + 15 − n(M ∩ S)
n(M ∩ S) = 33 − 25 = 8 students [3]
Marking: Award [1] for finding n(at least one), [1] for correct formula, [1] for correct answer.
(b) Mathematics only = 18 − 8 = 10
P(Mathematics only) = 10/30 = 1/3 [2]
Marking: Award [1] for finding 10, [1] for correct probability.
(c) P(at least one) = 25/30 = 5/6 [2]
Marking: Award [1] for 25, [1] for simplification.
Question 18
(a) Modal class = 10 – 14 (highest frequency, 12) [1]
(b)
| Class | Midpoint (x) | Frequency (f) | f × x |
|---|---|---|---|
| 5 – 9 | 7 | 6 | 42 |
| 10 – 14 | 12 | 12 | 144 |
| 15 – 19 | 17 | 10 | 170 |
| 20 – 24 | 22 | 8 | 176 |
| 25 – 29 | 27 | 4 | 108 |
Total f × x = 42 + 144 + 170 + 176 + 108 = 640
Mean ≈ 640 ÷ 40 = 16 minutes [4]
Marking: Award [1] for correct midpoints, [1] for correct f×x values, [1] for correct sum, [1] for correct division.
(c) Students who took 20 min or more = 8 + 4 = 12
P(≥20 min) ≈ 12/40 = 3/10 [2]
Marking: Award [1] for correct frequency count, [1] for correct probability.
Question 19
(a) P(yellow) = 1 − 0.4 − 0.35 = 0.25 [2]
Marking: Award [1] for correct subtraction from 1, [1] for correct answer.
(b) Number of red counters = 0.4 × 80 = 32 [2]
Marking: Award [1] for correct multiplication, [1] for answer with context.
(c) Number of yellow counters = 0.25 × 80 = 20 [2]
Marking: Award [1] for correct multiplication, [1] for answer with context.
(d) When the first counter is not replaced, the total number of counters decreases from 80 to 79. This changes the denominator for the second pick, so the probabilities for the second pick depend on what was picked first. The events are not independent. [2]
Marking: Award [1] for mentioning the total changes, [1] for explaining dependence.
Question 20
(a) Mean of Team A = (45 + 52 + 38 + 60 + 48 + 55) ÷ 6 = 298 ÷ 6 = 49.7 points (or 49 2/3) [2]
Marking: Award [1] for correct sum, [1] for correct division.
(b) Mean of Team B = (42 + 50 + 44 + 58 + 50 + 46) ÷ 6 = 290 ÷ 6 = 48.3 points (or 48 1/3) [2]
Marking: Award [1] for correct sum, [1] for correct division.
(c) Range of Team A = 60 − 38 = 22 points [1]
(d) Range of Team B = 58 − 42 = 16 points [1]
(e) Team B performed more consistently because it has a smaller range (16 compared to 22). A smaller range indicates that the scores are closer together and less spread out, meaning more consistent performance. [2]
Marking: Award [1] for identifying Team B, [1] for linking smaller range to consistency.
Total: 50 marks