Mathematics JAMB, WAEC, NECO AND NABTEB Official Past Questions

820

(a) Copy and complete the following table for the relation \(y = \frac{5}{2} + x – 4x^{2}\)

x -2.0 -1.5 -1.0 -0.5 0 0.5 1 1.5 2.0
y -15.5     1 2.5        

(b) Using a scale of 2cm to 1 unit on the x- axis and 2cm to 5 units on the y- axis, draw the graph of the relation for \(-2.0 \leq x \leq 2.0\).

(c) What is the maximum value of y?

(d) From your graph, obtain the roots of the equation \(8x^{2} – 2x – 5 = 0\)

View Answer & Discuss WAEC 1992
821

(a) 

Calculate the area of the shaded segment of the circle shown in the diagram [Take \(\pi = \frac{22}{7}\)]

(b) A tin has radius 3cm and height 6cm. Find the (i) total surface area of the tin ; (ii) volume, in litres, that will fill the tin to capacity, correct to two decimal places. 

[Take \(\pi = \frac{22}{7}\)]

View Answer & Discuss WAEC 1992
822

(a) Using a ruler and a pair of compasses only, construct: (i) a triangle ABC such that |AB| = 5cm, |AC| = 7.5cm and < CAB = 120°; (ii) the locus \(l_{1}\) of points equidistant from A and B; (iii) the locus \(l_{2}\) of points equidistant from AB and AC which passes through triangle ABC .

(b) Label the point P where \(l_{1}\) and \(l_{2}\) intersect.

(c) Measure |CP|.

View Answer & Discuss WAEC 1992
823

(a) If \(17x = 375^{2} – 356^{2}\), find the exact value of x.

(b) If \(4^{x} = 2^{\frac{1}{2}} \times 8\), find x.

(c) The sum of the first 9 terms of an A.P is 72 and the sum of the next 4 terms is 71, find the A.P.

View Answer & Discuss WAEC 1992
824

(a) In a game, a fair die is rolled once and two unbiased coins are tossed at once. What is the probability of obtaining 3 and a tail?

(b) A box contains 10 marbles, 7 of which are black and 3 are red. Two marbles are drawn one after the other without replacement. Find the probability of getting:

(i) a red, then a black marble ; (ii) two black marbles.

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825

(a) The sides PQ and PR of \(\Delta\) PQR are produced to T and S respectively, such that TQR = 131° and < QRS = 98°. Find < QPR.

(b) The circumference of a circular track is 400m. Find its radius, correct to the nearest metre. [Take \(\pi = \frac{22}{7}\)]

View Answer & Discuss WAEC 1992
826

(a) The angle of a sector of a circle radius 7cm is 108°. Calculate the perimeter of the sector. [Take \(\pi = \frac{22}{7}\)]

(b) A boat is on the same horizontal level as the foot of a cliff, and the angle of depression of the boat from the top of the cliff is 30°. If the boat is 120m away from the foot of the cliff, find the height of the cliff correct to three significant figures.

View Answer & Discuss WAEC 1992
827

(a) Solve the following pair of simultaneous equations: \(2x + 5y = 6\frac{1}{2} ; 5x – 2y = 9\)

(b) If \(\log_{10} (2x + 1) – \log_{10} (3x – 2) = 1\), find x.

View Answer & Discuss WAEC 1992
828

(a) If \(9^{2x – 1} = \frac{81^{x – 2}}{3^{x}}\), find x.

(b) Without using Mathematical Tables, evaluate: \(\sqrt{\frac{0.81 \times 10^{-5}}{2.25 \times 10^{7}}}\)

View Answer & Discuss WAEC 1992
829

P and Q are two points on latitude 55°N and their longitudes are 33°W and 20°E respectively. Calculate the distance between P and Q measured along 

(a) the parallel of latitude ;

(b) a great circle. 

[Take \(\pi = \frac{22}{7}\) and radius of the earth = 6400km].

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830

The table below shows the frequency distribution of the marks scored by fifty students in an examination.

Marks (%) 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99
Freq 2 3 4 6 13 10 5 3 2 2

(a) Draw the cumulative frequency curve for the distribution.

(b) Use your curve to estimate the : (i) upper quartile; (ii) pass mark if 60% of the students passed.

 

View Answer & Discuss WAEC 1993
831

(a) Copy and complete the following table of values for \(y = 3\sin 2\theta – \cos \theta\).

\(\theta\) 30° 60° 90° 120° 150° 180°
y -1.0     0     1.0

(b) Using a scale of 2cm to 30° on the \(\theta\) axis and 2cm to 1 unit on the y- axis, draw the graph of \(y = 3 \sin 2\theta – \cos \theta\) for \(0° \leq \theta \leq 180°\).

(c) Use your graph to find the : (i) solution of the equation \(3 \sin 2\theta – \cos \theta = 0\), correct to the nearest degree; (ii) maximum value of y, correct to one decimal place.

 

View Answer & Discuss WAEC 1993
832

(a) What is the 25th term of 5, 9, 13,… ?

(b) Find the 5th term of \(\frac{8}{9}, \frac{-4}{3}, 2, …\).

(c) The 3rd and 6th terms of a G.P are \(48\) and \(14\frac{2}{9}\) respectively. Write down the first four terms of the G.P.

View Answer & Discuss WAEC 1993
833

(a) Prove that the angle which an arc of a circle subtends at the centre is twice that which it subtends at any point on the remaining part of the circumference.

(b) 

In the diagram, O is the centre of the circle ACDB. If < CAO = 26° and < AOB = 130°. Calculate : (i) < OBC ; (ii) < COB.

View Answer & Discuss WAEC 1993
834

(a) 

In the diagram, BA is parallel to DE. Find the value of x.

(b) Illustrate graphically and shade the region in which inequalities \(y – 2x < 5 ; 2y + x \geq 4 ; y + 2x \leq 10\) are satisfied.

View Answer & Discuss WAEC 1993
835

(a)(i) Given that \(\log_{10} 5 = 0.699\) and \(\log_{10} 3 = 0.477\), find \(\log_{10} 45\), without using Mathematical tables.

(ii) Hence, solve \(x^{0.8265} = 45\).

(b) Use Mathematical tables to evaluate \(\sqrt{\frac{2.067}{0.0348 \times 0.538}}\)

View Answer & Discuss WAEC 1993
836

A box contains identical balls of which 12 are red, 16 white and 8 blue. Three balls are drawn from the box one after the other without replacement. Find the probability that :

(a) three are red;

(b) the first is blue and the other two are red;

(c) two are white and one is blue.

View Answer & Discuss WAEC 1993
837

(a) Simplify \(\frac{3}{m + 2n} – \frac{2}{m – 3n}\)

(b) A number is made up of two digits. The sum of the digits is 11. If the digits are interchanged, the original number is increased by 9. Find the number.

View Answer & Discuss WAEC 1993
838

A simple measuring device is used at points X and Y on the same horizontal level to measure the angles of elevation of the peak P of a certain mountain. If X is known to 5,200m above sea level, /XY/ = 4,000m and the measurements of the angles of elevation of P at X and Y are 15° and 35° respectively, find the height of the mountain. (Take \(\tan 15 = 0.3\) and \(\tan 35 = 0.7\))

View Answer & Discuss WAEC 1993
839

The universal set \(\varepsilon\) is the set of all integers and the subset P, Q, R of \(\varepsilon\) are given by:

\(P = {x : x < 0} ; Q = {… , -5, -3, -1, 1, 3, 5} ; R = {x : -2 \leq x < 7}\)

(a) Find \(Q \cap R\).

(b) Find \(R’\) where R’ is the complement of R with respect to \(\varepsilon\).

(c) Find \(P’ \cup R’\)

(d) List the members of \((P \cap Q)’\).

View Answer & Discuss WAEC 1993
840

(a) Simplify, without using Mathematical tables: \(\log_{10} (\frac{30}{16}) – 2 \log_{10} (\frac{5}{9}) + \log_{10} (\frac{400}{243})\)

(b) Without using Mathematical tables, calculate \(\sqrt{\frac{P}{Q}}\) where \(P = 3.6 \times 10^{-3}\) and \(Q = 2.25 \times 10^{6}\), leaving your answer in standard form.

View Answer & Discuss WAEC 1993