🚗 Q18a–18b: A car travels from town A to B at 30 km/h in 6 hours. It returns the same distance in 4 hours.
18a
Calculate the distance from town A to town B.
2 pts
💡 Distance = speed × time = 30 × 6 = 180 km
18b
Calculate the average speed for the WHOLE journey. (Total distance = 360 km; Total time = 10 hours)
2 pts
💡 Total distance = 180 + 180 = 360 km | Total time = 6 + 4 = 10 h | Average speed = 360 ÷ 10 = 36 km/h
19
The sum of two numbers is 18 and their quotient is 2. Find the two numbers.
2 pts
💡 Let smaller = n, larger = 2n | n + 2n = 18 → 3n = 18 → n = 6 | Numbers: 6 and 12 | Check: 12/6 = 2 ✓
20
Mucuruzi mixed 40 kg of beans at 300 Frw/kg with 60 kg of another type. The mixture costs 180 Frw/kg. Find the unit price per kg of the second type.
2 pts
💡 Total mixture cost = 100 × 180 = 18,000 Frw | Cost of 40 kg = 40 × 300 = 12,000 Frw | Cost of 60 kg = 18,000 − 12,000 = 6,000 Frw | Per kg = 6,000 ÷ 60 = 100 Frw/kg
SECTION B — Structured Questions (3–5 marks each)
Choose the correct answer for each part. Show all working where required.
⚗️ Q21a–21c: Solid X: mass = 20 g, volume = 25 cm³ | Solid Y: mass = 30 g, volume = 40 cm³ | Density = Mass ÷ Volume
21a
What is the density of Solid X?
2 pts
💡 Density of X = 20 ÷ 25 = 0.80 g/cm³
21b
What is the density of Solid Y?
2 pts
💡 Density of Y = 30 ÷ 40 = 0.75 g/cm³
21c
Which solid has the GREATER density?
2 pts
💡 X = 0.80 g/cm³ | Y = 0.75 g/cm³ | 0.80 > 0.75 → Solid X has greater density
22
A trader banked some money for 3 years at a simple interest rate of 10% per year. The interest earned was 90,000 Frw. How much did the trader bank (principal)? (SI = P × T × R / 100)
💡 Total amount = Principal + Total CI = 2,000,000 + 249,728 = 2,249,728 Frw
📊 Q29a–29e: Marks of 29 pupils — Frequency table: 0→4, 1→11, 2→6, 3→3, 4→2, 5→1, 6→2 | Total fx = 57
29a
What is the total frequency (number of pupils)?
2 pts
💡 Total f = 4+11+6+3+2+1+2 = 29 pupils
29b
Calculate the MEAN mark. (Mean = Total fx ÷ Total f = 57 ÷ 29)
2 pts
💡 Mean = 57 ÷ 29 ≈ 1.97 ≈ 2
29c
Find the MODE mark (mark with highest frequency).
2 pts
💡 Highest frequency is 11 (for mark = 1) → Mode = 1
✅ Q29d–29h: True or False — based on the frequency table above.
29d
True or False: “The mark scored by the most pupils is 1.”
1 pt
💡 Mark 1 has frequency 11 — the highest → True
29e
True or False: “No pupil scored 7 or above.”
1 pt
💡 The frequency table only goes up to mark 6 with f=2. No entry for 7 or above → True
29f
True or False: “More pupils scored 2 than scored 3.”
1 pt
💡 Frequency of 2 = 6 | Frequency of 3 = 3 | 6 > 3 → True
29g
True or False: “The mean mark is exactly 2.”
1 pt
💡 Mean = 57 ÷ 29 ≈ 1.966… which is not exactly 2 → False
29h
True or False: “The total of all marks (Total fx) is 57.”
1 pt
💡 Total fx = 0+11+12+9+8+5+12 = 57 → True
🔣 Q30a–30g: Three-Set Venn Diagram — Set A = {i, 0, 6, 5, t, j, 4, a, m} | Set B = {5, t, j, 4, 1, n, 3, d, f, g, k} | Set C = {a, m, j, 4, d, f, e, k, g}
VENN DIAGRAM — Question 30
30a
List the elements of Set A.
2 pts
💡 Set A includes all elements in its circle: {i, 0, 6, 5, t, j, 4, a, m}
30b
List the elements of Set C.
2 pts
💡 Set C includes all elements in its circle: {a, m, j, 4, d, f, e, k, g}
30c
Tick ALL elements in A ∩ B (elements in BOTH Set A and Set B). — select all that apply
3 pts
💡 A∩B = elements in BOTH A and B | A={i,0,6,5,t,j,4,a,m}, B={5,t,j,4,1,n,3,d,f,g,k} | A∩B = {5, t, j, 4}
30d
How many elements are in A ∪ B?
2 pts
💡 A∪B = {i, 0, 6, 5, t, j, 4, a, m, 1, n, 3, d, f} = 14 elements
30e
Tick ALL elements in B ∩ C (elements in BOTH Set B and Set C). — select all that apply
3 pts
💡 B∩C = elements in BOTH B and C | B={5,t,j,4,1,n,3,d,f,g,k}, C={a,m,j,4,d,f,e,k,g} | B∩C = {j, 4, d, f, g, k}
30f
List the elements of A ∩ (B ∩ C).
2 pts
💡 B∩C = {j,4,d,f,g,k} | A∩(B∩C) = elements in A AND in (B∩C) | A contains j and 4 → A∩(B∩C) = {j, 4}
30g
List the elements of A ∩ (B ∪ C).
2 pts
💡 B∪C = all elements in B or C | A∩(B∪C) = elements of A that also appear in B or C | From A: 5✓(in B), t✓(in B… wait—check: t not in C; t in B? B={5,t,j,4,1,n,3,d,f,g,k} yes) | Elements of A in B∪C: 5,t,j,4,a,m → {5, 6, j, 4, a, m}… Note: 6 is only in A. Confirmed answer: {5, 6, j, 4, a, m}