Mathematics JAMB, WAEC, NECO AND NABTEB Official Past Questions

841

(a) Two points X(32°N, 47°W) and Y(32°N, 25°E) are on the earth’s surface. If it takes an aeroplane 11 hours to fly from X to Y along the parallel of latitude, calculate its speed, correct to the nearest kilometre per hour. [Radius of the earth = 6400km; \(\pi = \frac{22}{7}\)]

(b) Two observers P and Q, 15metres apart observe a kite (K) in the same vertical plane and from the same side of the kite. The angles of elevation of the kite from P and Q are 35° and 45° respectively. Find the height of the kite to the nearest metre.

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842

(a) The fourth term of an A.P is 37 and 6th term is 12 more than the fourth term . Find the first and seventh terms.

(b) If \(P = {1, 2, 3, 4}\) and \(Q = {3, 5, 6}\), find (i) \(P \cap Q\) ; (ii) \(P \cup Q\) ; (iii) \((P \cap Q) \cup Q\) ; (iv) \((P \cap Q) \cup P\).

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843

(a) Copy and complete the following table of values for \(y = 2x^{2} – 9x – 1\).

x -1 0 1 2 3 4 5 6
y   -1 -8 -11       17

(b) Using a scale of 2cm to represent 1 unit on the x- axis and 2cm to represent 5 units on the y- axis, draw the graph of \(y = 2x^{2} – 9x – 1\).

(c) Use your graph to find the : (i) roots of the equation \(2x^{2} – 9x = 4\), correct to one decimal place ; (ii) gradient of the curve \(y = 2x^{2} – 9x – 1\) at x = 3.

 

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844

The table below gives the ages, to the nearest 5 years of 50 people.

Age in years 10 15 20 25 30
No of people 8 19 10 7 6

(a) Construct a cumulative frequency table for the distribution.

(b) Draw a cumulative frequency curve (Ogive)

(c) From your Ogive, find the : (i) median age ; (ii) number of people who are at most 15 years of age ; (iii) number of people who are between 20 and 25 years of age.

 

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845

(a) Using a ruler and a pair of compasses only, construct (i) a triangle XYZ in which /YZ/ = 8cm, < XYZ = 60° and < XZY = 75°. Measure /XY/; (ii) the locus \(l_{1}\) of points equidistant from Y and Z ; (iii) the locus \(l_{2}\) of points equidistant from XY and YZ.

(b) Measure QY where Q is the point of intersection of \(l_{1}\) and \(l_{2}\).

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846

A bag contains 12 white balls and 8 black balls, another contains 10 white balls and 15 black balls. If two balls are drawn, without replacement from each bag, find the probability that :

(a) all four balls are black ;

(b) exactly one of the four balls is white.

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847

(a) If \(\log_{10} (3x – 1) – \log_{10} 2 = 3\), find the value of x.

(b) Use logarithm tables to evaluate \(\sqrt{\frac{0.897 \times 3.536}{0.00249}}\), correct to 3 significant figures.

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848

The table below gives the frequency distribution of the marks obtained by some students in a scholarship examination.

Scores (x) 15 25 35 45 55 65 75
Freq (f) 1 4 12 24 18 8 3

(a) Calculate, correct to 3 significant figures, the mean mark.

(b) Find the : (i) mode ; (ii) range of the distribution.

 

 

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849

(a) Divide \(11111111_{two}\) by \(101_{two}\)

(b) A sector of radius 6 cm has an angle of 105° at the centre. Calculate its:

(i) perimeter ; (ii) area . [Take \(\pi = \frac{22}{7}\)]

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850

(a) A tower and a building stand on the same horizontal level. From the point P at the bottom of the building, the angle of elevation of the top, T of the tower is 65°. From the top Q of the building, the angle of elevation of the point T is 25°. If the building is 20m high, calculate the distance PT.

(b) Hence or otherwise, calculate the height of the tower. [Give your answers correct to 3 significant figures].

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851

(a) Evaluate, without using mathematical tables, \(17.57^{2} – 12.43^{2}\).

(b) Prove that angles in the same segment of a circle are equal.

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852

(a) Given that \(3 \times 9^{1 + x} = 27^{-x}\), find x.

(b) Evaluate \(\log_{10} \sqrt{35} + \log_{10} \sqrt{2} – \log_{10} \sqrt{7}\)

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853

A box contains 5 blue balls, 3 black balls and 2 red balls of the same size. A ball is selected at random from the box and then replaced. A second ball is then selected. Find the probability of obtaining

(a) two red balls ;

(b) two blue balls or two black balls ;

(c) one black and one red ball in any order.

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854

The table shows the scores of 2000 candidates in an entrance examination into a private secondary school.

% Mark 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90

No of 

pupils

68 184 294 402 480 310 164 98

(a) Prepare a cumulative frequency table and draw the cumulative frequency curve for the distribution.

(b) Use your curve to estimate the : (i) cut off mark, if 300 candidates are to be offered admission ; (ii) probability that a candidate picked at random, scored at least 45%.

 

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855

(a) A man travels from a village X on a bearing of 060° to a village Y which is 20km away. From Y, he travels to a village Z, on a bearing of 195°. If Z is directly east of X, calculate, correct to three significant figures, the distance of :

(i) Y from Z ; (ii) Z from X .

(b) An aircraft flies due South from an airfield on latitude 36°N, longitude 138°E to an airfield on latitude 36°S, longitude 138°E. 

(i) Calculate the distance travelled, correct to three significant figures ; (ii) if the speed of the aircraft is 800km per hour, calculate the time taken, correct to the nearest hour.

[Take \(\pi = \frac{22}{7}\), R = 6400km].

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856

(a) Using a ruler and a pair of compasses only, construct triangle ABC with /AB/ = 7.5cm, /BC/ = 8.1cm and < ABC = 105°.

(b) Locate a point D on BC such that /BD/ : /DC/ is 3 : 2.

(c) Through D, construct a line I perpendicular to BC.

(d) If the line I meets AC at P, measure /BP/.

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857

(a) Copy and complete the table for the relation \(y = 2 \cos 2x – 1\).

x 30° 60° 90° 120° 150° 180°
\(y = 2\cos 2x – 1\) 1.0 0         1.0

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

(c) On the same axis, draw the graph of \(y = \frac{1}{180} (x – 360)\)

(d) Use your graphs to find the : (i) values of x for which \(2 \cos 2x + \frac{1}{2} = 0\); (ii) roots of the equation \(2 \cos 2x – \frac{x}{180} + 1 = 0\).

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858

(a) Given that \(p = x + ym^{3}\), find m in terms of p, x and y.

(b) Using the method of completing the square, find the roots of the equation \(x^{2} – 6x + 7 = 0\), correct to 1 decimal place.

(c) The product of two consecutive positive odd numbers is 195. By constructing a quadratic equation and solving it, find the two numbers.

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859

(a) Using mathematical tables, find ; (i) \(2 \sin 63.35°\) ; (ii) \(\log \cos 44.74°\);

(b) Find the value of K given that \(\log K – \log (K – 2) = \log 5\);

(c) Use logarithm tables to evaluate \(\frac{(3.68)^{2} \times 6.705}{\sqrt{0.3581}}\)

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860

The frequency table shows the marks scored by 32 students in a test.

Marks scored 1 2 3 4 5 6 7 8 9 10
No of students 2 3 4 4 4 4 5 3 2 1

Find the :

(a)(i) mean ; (ii) median ; (iii) mode of the marks;

(b) percentage of the students who scored at least 8 marks.

 

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861

(a) A pack of 52 playing cards is shuffled and a card is drawn at random. Calculate the probability that it is either a five or a red nine.

[Hint : There are 4 fives and 2 red nines in a pack of 52 cards]

(b) P, Q and R are points in the same horizontal plane. The bearing of Q from P is 150° and the bearing of R from Q is 060°. If /PQ/ = 5m and /QR/ = 3m, find the bearing of R from P, correct to the nearest degree.

View Answer & Discuss WAEC 1995