IGCSE Maths Past Paper Solutions: 0580/42 February/March 2024 (Paper 4 Extended)
Full worked solutions to the Cambridge IGCSE Mathematics (0580) Paper 4 Extended exam paper from February/March 2024 (0580/42/F/M/24) — 12 questions, 130 marks, 2 hours 30 minutes. Attempt each question yourself first, then click “Show solution” to check your working step by step.
A grocer sells potatoes, mushrooms and carrots.
- (a) A customer buys 3 kg of mushrooms at $1.04 per kg and 4 kg of carrots at $1.28 per kg. Calculate the total cost. [2]
- (b) In one week, the ratio of the masses of vegetables sold by the grocer is potatoes : mushrooms : carrots = 11 : 8 : 6.
- Work out the mass of mushrooms sold as a percentage of the total mass. [2]
- The total mass of potatoes, mushrooms and carrots sold is 1500 kg. Find the mass of carrots the grocer sells this week. [2]
- The profit the grocer makes selling 1 kg of carrots is $0.75. Find the total profit the grocer makes selling carrots this week. [1]
- On the last day of the week, the grocer reduces the price of 1 kg of potatoes by 8% to $1.15. Calculate the original price of 1 kg of potatoes. [2]
- (c) The grocer buys 620 kg of onions, correct to the nearest 20 kg. He packs them into bags each containing 5 kg of onions, correct to the nearest 1 kg. Calculate the upper bound for the number of bags of onions that he packs. [3]
Show solution
- (a) 3 × 1.04 = 3.12. 4 × 1.28 = 5.12. Total = 3.12 + 5.12 = $8.24
- (b)(i) Total parts = 11+8+6 = 25. Mushrooms fraction = 8/25 = 32%
- (b)(ii) Carrots fraction = 6/25. Mass = (6/25) × 1500 = 360 kg
- (b)(iii) Profit = 360 × 0.75 = $270
- (b)(iv) The reduced price is 92% of the original: original × 0.92 = 1.15 → original = 1.15 ÷ 0.92 = $1.25
- (c) Upper bound of total mass (nearest 20 kg) = 620+10 = 630 kg. Lower bound of bag size (nearest 1 kg) = 5−0.5 = 4.5 kg. The upper bound for the number of bags is the largest total divided by the smallest bag size: 630 ÷ 4.5 = 140
A, B, C and D are points on a circle. ADX and BCX are straight lines. Angle BAD = x° and angle DCX = y°.
- (a) Explain why x = y. Give a geometrical reason for each statement you make. [2]
- (b) Show that triangle ABX is similar to triangle CDX. [2]
- (c) AD = 15 cm, DX = 9 cm and CX = 12 cm.
- Find BC. [3]
- Complete the statement: the ratio area of triangle ABX : area of triangle CDX = …… : 1. [1]
Show solution
- (a) ABCD is a cyclic quadrilateral, so opposite angles sum to 180°: angle BAD + angle BCD = 180° (opposite angles of a cyclic quadrilateral). Also angle BCD + angle DCX = 180° (angles on a straight line BCX). Since both sums equal 180° and share angle BCD, it follows that angle BAD = angle DCX, i.e. x = y
- (b) Angle AXB = angle CXD (it is the same angle at X, common to both triangles since A,D,X and B,C,X are straight lines). Angle XAB = angle BAD = x (same angle, as D lies on AX), and from part (a), x = y = angle DCX = angle XCD. So triangle ABX and triangle CDX have two pairs of equal angles, and are therefore similar (AA).
- (c)(i) AX = AD+DX = 15+9 = 24 cm. Since the triangles are similar with correspondence A↔C, B↔D, X↔X, the scale factor is AX/CX = 24/12 = 2. So BX = 2 × DX = 2 × 9 = 18 cm, and BC = BX − CX = 18−12 = 6 cm
- (c)(ii) The ratio of areas of similar triangles equals the square of the scale factor: 2² = 4 : 1
- (a) The table shows information about the marks gained by each of 10 students in a test.
| Mark | 15 | 16 | 17 | 18 | 19 | 20 |
|---|---|---|---|---|---|---|
| Frequency | 4 | 1 | 2 | 1 | 0 | 2 |
-
- Calculate the range. [1]
- Calculate the mean. [3]
- Find the median. [1]
- Write down the mode. [1]
- (b) Paulo’s mean mark for 7 homework tasks is 17. After completing the 8th task, his mean mark is 17.5. Calculate Paulo’s mark for the 8th task. [3]
- (c) The table shows the percentage scored by each of 100 students in their final exam.
| Percentage (p) | 0 < p ≤ 30 | 30 < p ≤ 50 | 50 < p ≤ 60 | 60 < p ≤ 70 | 70 < p ≤ 100 |
|---|---|---|---|---|---|
| Frequency | 12 | 18 | 35 | 20 | 15 |
On the grid, draw a histogram to show this information. [4]
Show solution
- (a)(i) Range = highest − lowest = 20−15 = 5
- (a)(ii) Mean = (15×4 + 16×1 + 17×2 + 18×1 + 19×0 + 20×2) ÷ 10 = (60+16+34+18+0+40)÷10 = 168÷10 = 16.8
- (a)(iii) Ordering the 10 marks: 15,15,15,15,16,17,17,18,20,20. The median is the mean of the 5th and 6th values: (16+17)÷2 = 16.5
- (a)(iv) The most frequent mark is 15, occurring 4 times: mode = 15
- (b) Total after 7 tasks = 17×7 = 119. Total after 8 tasks = 17.5×8 = 140. 8th mark = 140−119 = 21
- (c) Frequency density = frequency ÷ class width for each bar:
- 0<p≤30 (width 30): fd = 12÷30 = 0.4
- 30<p≤50 (width 20): fd = 18÷20 = 0.9
- 50<p≤60 (width 10): fd = 35÷10 = 3.5
- 60<p≤70 (width 10): fd = 20÷10 = 2.0
- 70<p≤100 (width 30): fd = 15÷30 = 0.5
- (a) The diagram shows a pyramid with a square base BCDE. The diagonals CE and BD intersect at M, and the vertex F is directly above M. BE = 12 cm and FM = 9 cm.
-
- Calculate the volume of the pyramid. [The volume, V, of a pyramid with base area A and height h is V = ⅓Ah.] [2]
- Calculate the total surface area of the pyramid. [5]
- (b) The diagram shows a toy made from a cone and a hemisphere. The base radius of the cone and the radius of the hemisphere are both r cm. The slant height of the cone is 3r cm. The total surface area of the toy is 304 cm².
Calculate the value of r. [The curved surface area, A, of a cone with radius r and slant height l is A = πrl.] [The curved surface area, A, of a sphere with radius r is A = 4πr².] [4]
Show solution
- (a)(i) Base area = 12×12 = 144 cm². Volume = ⅓ × 144 × 9 = 432 cm³
- (a)(ii) M is the centre of the square base, so the distance from M to the midpoint of any base edge is half of 12, i.e. 6 cm. The slant height of each triangular face (from F to the midpoint of a base edge) is found using Pythagoras: l = √(9²+6²) = √117 = 10.817 cm. Area of one triangular face = ½ × 12 × 10.817 = 64.90 cm². Four faces = 4 × 64.90 = 259.6 cm². Total surface area = base + 4 faces = 144 + 259.6 = 404 cm² (3 s.f.)
- (b) Curved surface of cone = πr(3r) = 3πr². Curved surface of hemisphere = half of a sphere’s curved surface = 2πr² (the flat circular face is where the two solids join, so it isn’t part of the outer surface). Total surface = 3πr² + 2πr² = 5πr² = 304. So r² = 304÷(5π) = 19.353, and r = √19.353 = r = 4.40 cm (3 s.f.)
- (a)
- Factorise. x² − x − 12 [2]
- Simplify. (x²−16) / (x²−x−12) [2]
- (b) Simplify. (2x−3)² − (x+1)² [3]
- (c) Write as a single fraction in its simplest form. (2x+4)/(x+1) − x/(x−3) [4]
- (d) Expand and simplify. (x−3)(x−5)(2x+1) [3]
- (e) Solve the simultaneous equations. You must show all your working.
x − 3y = 13
2x² − 9y = 116 [6]
Show solution
- (a)(i) Need two numbers multiplying to −12 and adding to −1: these are −4 and 3. (x−4)(x+3)
- (a)(ii) x²−16 = (x−4)(x+4) (difference of two squares). Dividing by (x−4)(x+3) and cancelling the common factor (x−4): (x+4)/(x+3)
- (b) (2x−3)² = 4x²−12x+9. (x+1)² = x²+2x+1. Subtracting: 4x²−12x+9−x²−2x−1 = 3x² − 14x + 8
- (c) Common denominator (x+1)(x−3): numerator = (2x+4)(x−3) − x(x+1) = (2x²−2x−12) − (x²+x) = x²−3x−12. (x² − 3x − 12) / [(x+1)(x−3)]
- (d) (x−3)(x−5) = x²−8x+15. Multiplying by (2x+1): x²(2x+1) −8x(2x+1)+15(2x+1) = 2x³+x²−16x²−8x+30x+15 = 2x³ − 15x² + 22x + 15
- (e) From the first equation, x = 13+3y. Substitute into the second: 2(13+3y)²−9y = 116. Expanding (13+3y)² = 169+78y+9y²: 2(169+78y+9y²)−9y = 116 → 18y²+147y+338 = 116 → 18y²+147y+222 = 0. Dividing by 3: 6y²+49y+74 = 0. Using the quadratic formula: discriminant = 49²−4(6)(74) = 2401−1776 = 625, √625 = 25. y = (−49±25)/12, giving y = −2 or y = −37/6. For y=−2: x = 13+3(−2) = 7. For y=−37/6: x = 13−37/2 = −5.5.
x = 7, y = −2 x = −5.5, y = −37/6 (−6.17)
The diagram shows triangle ABC with AB = 17.2 cm. Angle ABC = 54° and angle ACB = 68°. M lies on BC.
- (a) Calculate AC. [3]
- (b) M lies on BC and MC = 12.8 cm. Calculate AM. [3]
- (c) Calculate the shortest distance from A to BC. [3]
Show solution
- (a) Angle BAC = 180−54−68 = 58°. By the sine rule: AC/sin(ABC) = AB/sin(ACB) → AC = 17.2 × sin54° ÷ sin68° = 17.2 × 0.80902 ÷ 0.92718 = 15.0 cm (3 s.f.)
- (b) In triangle AMC, angle ACM = angle ACB = 68° (same angle, as M lies on BC), with AC ≈ 15.008 cm and MC = 12.8 cm. Using the cosine rule: AM² = AC²+MC²−2(AC)(MC)cos68° = 225.24+163.84−2(15.008)(12.8)(0.37461) = 225.24+163.84−143.94 = 245.14. AM = √245.14 = 15.7 cm (3 s.f.)
- (c) The shortest distance from A to line BC is the perpendicular height, which can be found using the right-angled triangle formed with angle B: height = AB × sin(ABC) = 17.2 × sin54° = 17.2 × 0.80902 = 13.9 cm (3 s.f.)
- (a) p = (8, −5) q = (−4, 5)
- Find 3q. [1]
-
- Find p − q. [1]
- Find |p − q|. [2]
- (b) In triangle OMN, O is the origin, OM→ = a and ON→ = b. S is a point on MN such that MS:SN = 5:3. Find, in terms of a and/or b, the position vector of S. Give your answer in its simplest form. [3]
Show solution
- (a)(i) 3q = 3×(−4, 5) = (−12, 15)
- (a)(ii)(a) p−q = (8−(−4), −5−5) = (12, −10)
- (a)(ii)(b) |p−q| = √(12²+(−10)²) = √(144+100) = √244 = 15.6 (3 s.f.)
- (b) Since MS:SN = 5:3, S divides MN so that MS→ = ⅝MN→. Position vector of S = OM→ + ⅝(ON→−OM→) = a + ⅝(b−a) = ⅜a + ⅝b
- (a) On the axes, sketch the graph of y = 4−3x. [2]
- (b) On the axes, sketch the graph of y = −x². [2]
- (c)
- Find the coordinates of the turning points of the graph of y = 10+9x²−2x³. You must show all your working. [5]
- Determine whether each turning point is a maximum or a minimum. Show how you decide. [3]
Show solution
- (a) y=4−3x is a straight line with gradient −3 and y-intercept 4 (so it passes through (0,4) and crosses the x-axis at x=&frac43;), sloping downward from left to right.
- (b) y=−x² is a downward-opening parabola with vertex at the origin (0,0), symmetric about the y-axis, and lying entirely on or below the x-axis.
- (c)(i) dy/dx = 18x−6x² = 6x(3−x). Setting this to zero: x=0 or x=3. At x=0: y=10. At x=3: y=10+9(9)−2(27) = 10+81−54 = 37.
(0, 10) and (3, 37) - (c)(ii) d²y/dx² = 18−12x. At x=0: 18−0=18>0, so this is a minimum. At x=3: 18−36=−18<0, so this is a maximum.
- (a) Janna and Kamal each invest $8000. At the end of 12 years, they each have $12 800.
- Janna invests in an account that pays simple interest at a rate of r% per year. Calculate the value of r. [3]
- Kamal invests in an account that pays compound interest at a rate of R% per year. Calculate the value of R. [3]
- (b) The population of a city is growing exponentially at a rate of 1.8% per year. The population now is 260 000. Find the number of complete years from now when the population will first be more than 300 000. [3]
Show solution
- (a)(i) Total simple interest earned = 12800−8000 = 4800. Using I = Prt/100: 4800 = 8000 × r × 12 ÷ 100 = 960r. r = 5
- (a)(ii) Using 8000(1+R/100)¹² = 12800: (1+R/100)¹² = 1.6, so 1+R/100 = 1.61/12 = 1.03996. R = 4.00 (3 s.f.)
- (b) Solve 260000(1.018)n > 300000, i.e. (1.018)n > 1.15385. Testing values: at n=8, 1.018⁸ ≈ 1.1534 (still below); at n=9, 1.018⁹ ≈ 1.1742 (above 1.15385). So the population first exceeds 300 000 after 9 years
The table shows some values for y = 2x³+6x²−2.5.
| x | −3 | −2.5 | −2 | −1.5 | −1 | −0.5 | 0 | 0.5 | 1 |
|---|---|---|---|---|---|---|---|---|---|
| y | ? | 3.75 | 5.5 | 4.25 | 1.5 | ? | −2.5 | −0.75 | ? |
- (a) Complete the table. [3]
- (b) On the grid, draw the graph of y = 2x³+6x²−2.5 for −3 ≤ x ≤ 1. [4]
- (c) By drawing a suitable line on the graph, solve the equation 2x³+6x² = 4.5. [3]
- (d) The equation 2x³+6x²−2.5 = k has exactly two solutions. Write down the two possible values of k. [2]
Show solution
- (a) At x=−3: y = 2(−27)+6(9)−2.5 = −54+54−2.5 = −2.5. At x=−0.5: y = 2(−0.125)+6(0.25)−2.5 = −0.25+1.5−2.5 = −1.25. At x=1: y = 2(1)+6(1)−2.5 = 2+6−2.5 = 5.5.
x=−3: y=−2.5 x=−0.5: y=−1.25 x=1: y=5.5 - (b) Plot the nine points from the table and join them with a smooth curve. The curve has a local maximum near (−2, 5.5) and a local minimum near (0, −2.5).
- (c) Rearranging, 2x³+6x² = 4.5 is the same as 2x³+6x²−2.5 = 2, so draw the horizontal line y=2 and read off where it crosses the curve. Solving numerically confirms three crossings, at approximately
x = −2.7 x = −1.1 x = 0.8 (readings from the graph; small variation is acceptable) - (d) The curve has exactly two solutions for a given k only when the horizontal line y=k is tangent to the curve at a turning point — i.e. when k equals the local maximum or local minimum y-value: k = 5.5 or k = −2.5
f(x) = 1/x, x≠0 g(x) = 3x−5 h(x) = 2x
- (a) Find.
- gf(2) [2]
- g−1(x) [2]
- (b) Find in its simplest form g(x−2). [2]
- (c) Find the value of x when
- fg(x) = 0.1 [2]
- h(x)−g(7) = 0 [2]
Show solution
- (a)(i) f(2) = 1/2. g(1/2) = 3(1/2)−5 = 1.5−5 = −3.5
- (a)(ii) Let y=3x−5, so x=(y+5)/3. g−1(x) = (x+5)/3
- (b) g(x−2) = 3(x−2)−5 = 3x−6−5 = 3x − 11
- (c)(i) fg(x) = 1/(3x−5) = 0.1 → 3x−5 = 10 → 3x = 15 → x = 5
- (c)(ii) g(7) = 3(7)−5 = 16. So 2x = 16 = 2⁴ → x = 4
- (a) The diagram shows a circle of radius 12 cm, with a sector of angle 50° removed. Calculate the perimeter of the remaining shaded shape. [4]
- (b) The diagram in part (a) shows the top of a cylindrical cake with a slice removed. The volume of cake that remains is 3510 cm³. Calculate the height of the cake. [3]
Show solution
- (a) The remaining shape is the major sector, with angle 360−50 = 310°. Its perimeter consists of two straight radii (12 cm each) plus the major arc: arc length = (310/360) × 2π(12) = 0.86111 × 75.398 = 64.93 cm. Perimeter = 2(12) + 64.93 = 24 + 64.93 = 88.9 cm (3 s.f.)
- (b) The remaining cake is (310/360) of a full cylinder of radius 12 cm and height h: Volume = (310/360) × π(12)² × h = 0.86111 × 452.39 × h = 389.6h. Setting this equal to 3510: h = 3510 ÷ 389.6 = 9.01 cm (3 s.f.)