Pearson Edexcel International GCSE (9–1) · MATHEMATICS A · Unit
Unit 2
105 practice questions
Topics covered
Practice questions
41–48 of 48 · Normal
Question 41
4 marks · Normal
Answer and see the solution →A circular swimming pool has a diameter of 16 m. Water is pumped into the pool at a constant rate. The following table shows the depth of water after different times:
(a)[1 mark]Depth of water over time Time (minutes) Depth (m) 10 0.8 20 1.6 30 2.4 40 ? (b)[2 marks]Calculate the area of the surface of the pool. Give your answer in standard form.
(c)[1 mark]Express the answer from part (b) as an ordinary number.
Question 42
4 marks · Normal
Answer and see the solution →A rectangle has a length of 4x cm and a width of 2x cm. The area of the rectangle is equal to 72 cm².
(a)[1 mark]Write down an equation in terms of x for the area of the rectangle.
(b)[2 marks]Solve your equation to find the value of x.
(c)[1 mark]Calculate the perimeter of the rectangle.
Question 43
4 marks · Normal
Answer and see the solution →Amira draws a circle with a radius of 5 cm.
(a)[2 marks]Calculate the area of the circle. Give your answer correct to 1 decimal place.
(b)[2 marks]Amira increases the radius by 20%. What is the new area of the circle, correct to 1 decimal place?
Question 44
4 marks · Normal
Answer and see the solution →The diameter of a circular pond is 14 m. Water is being added at a rate that increases the depth from 0.9 m to 1.15 m over 5 hours.
(a)[1 mark]Write the formula for calculating the volume of water added, using π, diameter and change in depth.
(b)[2 marks]Calculate the volume of water added to the pond over 5 hours. Give your answer to the nearest whole number.
(c)[1 mark]Express your answer to part (b) in standard form.
Question 45
4 marks · Normal
Answer and see the solution →A circle has a diameter of 18 cm.
a) Work out the radius of the circle.
b) The area of the circle is decreased by 10%. Work out the new area of the circle. Give your answer in cm² to 2 decimal places.
(a)[1 mark]Work out the radius of the circle.
(b)[3 marks]The area of the circle is decreased by 10%. Work out the new area of the circle. Give your answer in cm² to 2 decimal places.
Question 46
5 marks · Normal
Answer and see the solution →1. Scientists measured the mass of a grain of rice as 0.000028 kg. In a laboratory, a student investigates a relationship using the formula , where is mass in kilograms and m/s.
(a)[1 mark]Express the mass of one grain of rice in standard form.
(b)[2 marks]Calculate and write your answer in standard form.
(c)[2 marks]Using your answers to (a) and (b), work out the value of for one grain of rice. Give your answer in standard form.
Question 47
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 48
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.