Pearson Edexcel International GCSE (9–1) · MATHEMATICS A · Unit
Unit 2
105 practice questions
Topics covered
Practice questions
101–105 of 105
Question 101
4 marks · Normal
Answer and see the solution →2. The heights (in metres) of five sunflowers are measured and shown below: 1.24, 1.09, 1.32, 1.14, 1.28. A sixth sunflower grows to metres.
(a)[2 marks]Calculate the mean height of the five sunflowers.
(b)[2 marks]If the mean increases to 1.25 metres after adding the sixth sunflower, find the value of .
Question 102
5 marks · Normal
Answer and see the solution →3. The following information is about a circle with centre O.
Circle with chord AB and radius OC perpendicular to AB. (a)[3 marks]If OC = 3 cm and AB = 4 cm, calculate the radius OA of the circle.
(b)[2 marks]Write your answer to (a) in standard form.
Question 103
6 marks · Hard
Answer and see the solution →A scientist records the diameters of two distinct circular cells, Cell A and Cell B. The diameter of Cell A is 0.0036 mm and the diameter of Cell B is 2.8 × 10^{-2} mm.
(a)[2 marks]Express the diameter of each cell in standard form.
(b)[4 marks]The scientist wants to find out how many times bigger the area of Cell B is compared to the area of Cell A. Use the formula for the area of a circle, , and give your answer in standard form to 2 significant figures.
Question 104
5 marks · Hard
Answer and see the solution →The temperature of a chemical experiment is monitored every 2 minutes, giving the readings in °C: 20.7, 21.5, 21.9, 22.6, 23.1, 22.3. The experimenter models the temperature change with the linear equation T = a + bt, where t is the time in minutes.
(a)[2 marks]Calculate the mean and median temperature from the data.
(b)[2 marks]Given that at t = 0, T = 20.7, and at t = 10, T = 23.1, find the values of a and b.
(c)[1 mark]According to the model, what will the temperature be after 12 minutes? Give your answer to 1 decimal place.
Question 105
6 marks · Hard
Answer and see the solution →In the diagram below, points A and B lie on the circumference of the circle with centre O. The straight line AB is a chord, and OC is a radius perpendicular to AB, meeting AB at M. The length of OC is 7 cm and the distance from O to M is 4 cm.
Circle with centre O. AB is a chord. OC is a radius, perpendicular to AB, meeting AB at M. OC = 7 cm, OM = 4 cm. (a)[2 marks]Calculate the length MC.
(b)[3 marks]Find the length AB.
(c)[1 mark]Express your answer to part (b) in standard form.