Pearson Edexcel International GCSE (9–1) · MATHEMATICS A · Unit
Unit 9
105 practice questions
Topics covered
Practice questions
81–90 of 105
Question 81
2 marks · Normal
Answer and see the solution →Two histograms represent the marks for two different exams, Exam X and Exam Y. The modal class of Exam X is 30–40 marks, while the modal class of Exam Y is 50–60 marks.
Which exam did more students score higher marks in, and how can you tell from the histograms?
Question 82
3 marks · Normal
Answer and see the solution →A grouped frequency table shows the heights (in cm) of a sample of plants:
Height (cm) Frequency 0 < h \leq 10 4 10 < h \leq 20 10 20 < h \leq 40 12 Work out the frequency density for each group.
Question 83
3 marks · Normal
Answer and see the solution →A histogram shows the times taken by 60 runners to complete a race. The modal class interval is 40–50 minutes.
Explain, using evidence from the histogram, how you can estimate the number of runners who finished in less than 40 minutes.
Question 84
3 marks · Normal
Answer and see the solution →The histograms below each show the distribution of the finishing times (in minutes) for two groups, Group P and Group Q, in a 10 km race. Both groups contain exactly 60 runners. Both axes are labelled the same and the scales match.
Histogram distributions for Group P and Group Q Table: Histogram class data for Group P and Group Q Time (min) Frequency density (P) Frequency density (Q) 30 < t ≤ 40 1.8 0.7 40 < t ≤ 50 1.2 2.0 50 < t ≤ 60 0.7 1.3 60 < t ≤ 70 0.3 0.4 (a)[1 mark]Which group had a greater proportion of fast runners? Give a reason for your answer.
(b)[2 marks]Which group had finishing times more spread out? Explain why using the histogram.
Question 85
4 marks · Normal
Answer and see the solution →The histogram below shows the time taken, in minutes, for a group of students to complete a test.
Histogram for test completion times The class widths for all intervals are equal except for the last bar, which covers a wider interval.
(a)[1 mark]Use the histogram to write down the class width for the interval 50 < t ≤ 60.
(b)[1 mark]Work out the frequency (number of students) for the interval 40 < t ≤ 50.
(c)[2 marks]Write down the total number of students in the group.
Question 86
2 marks · Hard
Answer and see the solution →The grouped frequency table below shows the ages of people attending a workshop.
Age (years) Frequency 10 < a \leq 20 8 20 < a \leq 30 16 30 < a \leq 50 12 What is the frequency density for the group 20 < a \leq 30?
Question 87
4 marks · Hard
Answer and see the solution →The histogram shows the times taken by 60 students to finish a computer game.
Calculate the total number of students who finished the game in more than 10 minutes but no more than 25 minutes.
Question 88
4 marks · Hard
Answer and see the solution →The histograms below show the distribution of journey times (in minutes) to school for two local schools, Alpha and Beta. Both schools had the same total number of students surveyed.
Journey Times to School Compare the two distributions. Give two differences and what they show about the journey times for Alpha and Beta.
Question 89
8 marks · Easy
Answer and see the solution →A function is defined by the curve . The diagram below shows part of this curve.
(a)The curve \( y = x^2 \) and two highlighted points. Find the gradient of the curve at the point A.
(i)[3 marks]Draw a tangent at point A and estimate its gradient. Show your working.
(b)A cuboid has an edge OA of 6 cm and OB of 8 cm. OC is perpendicular to both OA and OB and has a length of 5 cm. O, A, B, and C are adjacent vertices joining at one corner.
Use Pythagoras’ theorem in 3D to find the length of the diagonal OC.
(i)[2 marks]Calculate the length OC, giving your answer correct to one decimal place.
(c)[3 marks]Explain how the ideas of gradient (from part a) and using Pythagoras’ theorem in three dimensions (from part b) are similar when working with curves and 3D shapes.
Question 90
8 marks · Easy
Answer and see the solution →The graph of for is sketched below.
(a)[2 marks]Graph sketch of \( y = f(x) \) Write down the equation of the graph reflected in the x-axis.
(b)[2 marks]A right-angled triangle has sides AB = 4 cm, BC = 3 cm and the right angle is at B. The triangle is a face on a cuboid.
Calculate the length AC.
(c)[2 marks]The cuboid from part b has a height BD = 8 cm, perpendicular to triangle ABC. Find the length from A to D.
(d)[2 marks]Describe how the transformation in part a and the 3D length calculation in part c both involve symmetry or distance.