IGCSE · Mathematics 0580 · Number

Ratio & proportion: IGCSE Mathematics questions with answers

Free Ratio & proportion questions for IGCSE Mathematics (0580), part of Number. Each question has the answer and the marking points an examiner would look for.

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Ratio & proportion practice questions

Question 1Structured · 4 marksA* challenge

In a club, the ratio boys : girls = 5 : 2.
8 boys leave the club and 22 girls join the club.
There are now the same number of boys and girls.
Find how many members the club had at the start.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
70
5k − 8 = 2k + 22 (or equivalent) M2
k = 10 A1
70 A1
4
Question 2Structured · 13 marksA* challenge

Alloy A contains copper and zinc in the ratio 3 : 2 by mass.
Alloy B contains copper, zinc and tin in the ratio 5 : 3 : 2 by mass.

(a)

a kg of alloy A and b kg of alloy B are melted together. In the mixture, the ratio copper : zinc is 13 : 8.
Find a : b in its simplest form and the percentage of the mixture that is tin.

[5]
(b)

A different mixture of alloys A and B has copper : zinc between 8 : 5 and 13 : 8.
Find the range of possible values of the percentage of the mixture that is tin.

[4]
(c)

Pure copper is added to 10 kg of the mixture from part (a) so that the ratio copper : zinc becomes 2 : 1.
Find the mass of copper added, and the ratio copper : zinc : tin in the final alloy in its simplest form.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)a : b = 1 : 4; 16%
copper 0.6a + 0.5b, zinc 0.4a + 0.3b B1
8(0.6a + 0.5b) = 13(0.4a + 0.3b) M1
0.1b = 0.4a, a : b = 1 : 4 A1
tin = 0.2b = 0.8a out of 5a M1
16% A1
5
(b)1313% to 16%
8(0.4a + 0.3b) = 5(0.6a + 0.5b) gives b = 2a M1
tin = 0.4a3a = 1313% A1
the copper : zinc ratio and the tin percentage both increase as the proportion of B increases M1
between 1313% and 16% A1
4
(c)1.2 kg; 32 : 16 : 8 → 4 : 2 : 1
10 kg contains copper 5.2 kg, zinc 3.2 kg, tin 1.6 kg B1
5.2 + c = 2 × 3.2 M1
c = 1.2 kg A1
6.4 : 3.2 : 1.6 = 4 : 2 : 1 B1
4
Question 3Structured · 4 marks
(a)

Share $220 in the ratio 4 : 3 : 4.

[2]
(b)

In a club the ratio of boys to girls is 3 : 6. There are 9 more girls than boys. Work out the total number of members.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)$80 : $60 : $80
220 ÷ 11 = 20 M1
All three correct A1
2
(b)27
9 ÷ 3 = 3 M1
27 A1
2
Question 4Structured · 4 marksA* challenge

Amir, Bella and Chen share some money.
The ratio Amir’s share : Bella’s share = 2 : 5.
The ratio Bella’s share : Chen’s share = 4 : 3.
Chen receives $245 more than Amir.
Calculate the total amount of money they share.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
$1505
A : B : C = 8 : 20 : 15 M1
15 − 8 = 7 parts = $245 M1
1 part = $35 M1
1505 A1
4
Question 5Structured · 4 marksA* challenge

In a club, the ratio boys : girls = 7 : 4.
7 boys leave the club and 29 girls join the club.
There are now the same number of boys and girls.
Find how many members the club had at the start.

[4]
Show answers and mark scheme
PartAnswer and marking pointsMarks
132
7k − 7 = 4k + 29 (or equivalent) M2
k = 12 A1
132 A1
4
Question 6Structured · 4 marks
(a)

Share $420 in the ratio 1 : 3 : 2.

[2]
(b)

In a club the ratio of boys to girls is 2 : 4. There are 18 more girls than boys. Work out the total number of members.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)$70 : $210 : $140
420 ÷ 6 = 70 M1
All three correct A1
2
(b)54
18 ÷ 2 = 9 M1
54 A1
2

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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in