## Mathematics 2018 Past Questions | JAMB

Study the following Mathematics past questions and answers for JAMB, WAEC NECO and Post-JAMB. Get prepared with official past questions and answers for upcoming examinations.

**21. **A boy walks 800m in 20 minutes. Calculate his average speed in Km/H

**A.**2.4**B.**4**C.**24- D. 402.4

**Correct Option: Answer is A**

Speed = Distance/Time

Speed =

Distance =800m/1000m = 8/10

Time = 60/20 = 3

Speed = 8/10 * 3

2.4km/h

**22. **A car uses one litre of petrol for every 14km. If one litre of petrol cost N63.00, how far can the car go with N900.00 worth of petrol?

**A.**420Km**B.**405Km**C.**210Km**D.**200Km

**Correct Option: Answer is D**

since 1 litre cost ₦63

So ₦900 is the cost of 900/63 litres

= 14.2857 litres of petrol

∴ The car uses 1 litre for 14km

So 14.2857 litres will be used for (14.2857 x 14)

= 200km

Answer is D

**23.**

In the diagram, GI is a tangent to the circle at H. If EF||GI, calculate the size of ∠EHF

**A.**126°**B.**72°**C.**54°**D.**28°

**Correct Option: Answer is B**

∠FHI = 54° = ∠EFH (alternating angles)

∠FEH = ∠EFH (isosceles triangle)

∠EHF + ∠FEH + ∠EFH = 180° (sum of the angles in a triangle)

∠EHF = 180° – (∠FEH + ∠EFH)

∠EHF = 180° – (54° – 54°) = 180° – 108°

∠EHF = 72°

**24. **How many times, correct to the nearest whole number, will a man run round a circular track of diameter 100m to cover a distance of 1000m?

**A.**3**B.**4**C.**5**D.**6

**Correct Option: Answer is B**

In terms of distance, a circle has a total distance or perimeter of 2πr or πd

Where r is radius and d is the diameter

So perimeter = \(\frac{22}{7}\) x 100

= 314.2857m

To cover a distance of 1000m, he is going to round the circular track for \(\frac{1000}{314.2857}\) = 3.18

\(\approxeq\) 3 (to the nearest whole number)

**25.** How many times, correct to the nearest whole number, will a man run round a circular track of diameter 100m to cover a distance of 1000m?

**A.**3**B**. 4**C**. 5**D**. 6

**Correct Option: Answer is C**

**26. **\(\frac{0.00256 \times 0.0064}{0.025 \times 0.08}\)

**A.**8.8 x 10\(^{-1}\)**B.**8.8 x 10\(^{-2}\)**C.**8.8 x 10\(^{-3}\)**D.**8.8 x 10\(^{3}\)

**Correct Option: Answer is C**

**27. **Two sisters, Taiwo and Kehinde, own a store. The ratio of Taiwo’s share to Kehinde’s is 11:9. Later Kehinde sells $\frac{\mathrm{2/}}{3}$ of her share to Taiwo for N720.00. Find the value of the store

**A.**N1,080.00**B.**N2,400.00**C.**N3,000.00**D.**N3,600.00

**Correct Option: Answer is B**

Total ratio = 11 + 9 = 20

Taiwo’s share = 11/20

Kehinde’s share = 9/20

2/3 × 9/20 = 3/10 (percentage of total shares sold to Taiwo)

3x/10 = ₦720

3x = ₦7200

x = ₦2400

**28. **A room is 12m long, 9m wide and 8m high. Find the cosine of the angle which a diagonal of the room makes with the floor of the room

**A.**15/17**B.**9/17**C.**8/15**D.**12/17

**Correct Option: Answer is A**

\(a^2 = 12^2 + 9^2\)

\(a = \sqrt{12^2 + 9^2}\)

\(a = 15\text{ m}\)

\(b^2 = 15^2 + 8^2\)

\(b = \sqrt{15^2 + 8^2}\)

\(b = 17\text{ m}\)

cos Θ =a/b = 15/17

**29. **Divide the L.C.M of 48, 64 and 80 by their H.C.F

**A.**20**B.**30**C.**48**D.**60

**Correct Option: Answer is D**

LCM of 80, 64, 48 = 960

HCF of 80, 64, 48 = 16

960 $\xf7$ 16 = 60

**30. **Find the equation of the line through (5,7) parallel to the line 7x + 5y = 12

**A.**5x + 7y = 20**B.**7x + 5y = 70**C.**xy = 7**D.**15x + 17y = 90

**Correct Option: Answer is B**

\(m_1 = m_2\) (slopes are equal)

\(7x + 5y = 12\); make y the subject of the formula

\(5y = 12 – 7x\)

\(y = \frac{12-7x}{5} = \cfrac{12}{5} – \cfrac{7x}{5}\)

\(m_1 = -\cfrac{7}{5}\)

Line 2: \(y = mx + c\); since \(m_1 = m_2\)

\(y = -\cfrac{7}{5}x + c\)

Using point (5, 7), solve for c:

\(7 = -\cfrac{7}{5}(5) + c\)

\(c = 14\)

\(y = -\cfrac{7}{5}x + 14\)

\(5y = -7x + 70\)

\(7x + 5y = 70\)