Mathematics JAMB, WAEC, NECO AND NABTEB Official Past Questions

883

(a) Use logarithm tables to evaluate \(\frac{15.05 \times \sqrt{0.00695}}{6.95 \times 10^{2}}\).

(b) The first 5 students to arrive in a school on a Monday morning were 2 boys and 3 girls. Of these, two were chosen at random for an assignment. Find the probability that :

(i) both were boys ; (ii) the two were of different sexes.

View Answer & Discuss WAEC 1997
884

(a) Given that \(\frac{5y – x}{8y + 3x} = \frac{1}{5}\), find the value of \(\frac{x}{y}\) to two decimal places.

(b) If 3 is a root of the quadratic equation \(x^{2} + bx – 15 = 0\), determine the value of b. Find the other root.

View Answer & Discuss WAEC 1997
885

The table below shows how a company’s sales manager spent his 1995 annual salary.

Food 30%
Rent 18%
Car Maintenance 25%
Savings 12%
Taxes 5%
Others  10%

(a) Represent this information on a pie chart.

(b) Find his savings at the end of the year if his annual salary was N60,000.00.

 

View Answer & Discuss WAEC 1997
886

(a) Given that \(\sin x = \frac{5}{13}, 0° \leq x \leq 90°\), find \(\frac{\cos x – 2 \sin x }{2\tan x}\).

(b) 

 The diagram represents the vertical cross-section of a mountain with height NQ standing on a horizontal ground PRN. If the angles of elevation of the top of the mountain from P and R are 30° and 70° respectively and PR = 500m, calculate, correct to 3 significant figures :

(i) |QP| ; (ii) the height of the mountain.

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887

(a) The 6th term of an A.P is 35 and the 13th term is 77. Find the 20th term.

(b)  

The Venn diagram represents three subsets P, Q and R of the universal set U. Copy the Venn diagram. Shade and indicate the regions represented by (i) \(P \cap Q’ \cap R\) ; (ii) \(P’ \cap Q \cap R’\).

View Answer & Discuss WAEC 1997
888

(a) Copy and complete the binary multiplication table:

x 10 11 100 101
10 100   1000  
11 110   1100  
100     10000 10100

(b) Convert \(11.011_{two}\)  to a number in base ten.

(c) Simplify \(\frac{9.6 \times 10^{18}}{0.24 \times 10^{5}}\) and express your answer in the form \(P \times 10^{m}\) where 1 < P < 10 and m is an integer.

View Answer & Discuss WAEC 1997
889

The table below shows the number of eggs laid by the chickens in a man’s farm in a year.

No of eggs per year No of chickens
45 – 49 10
50 – 54 36
55 – 59 64
60 – 64 52
65 – 69 28
70 – 74 10

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

(b) Use your graph to find the interquartile range.

(c) If a woman buys a chicken from the farm, what is the probability that the chicken lays at least 60 eggs in a year?

 

View Answer & Discuss WAEC 1998
890

In the diagram, ASRTB represents a piece of string passing over a pulley of radius 10cm in a vertical plane. O is the centre of the pulley and AMB is a horizontal straight line touching the pulley at M. Angle SAB = 90° and angle TBA = 60°. 

(a) Calculate (i) the obtuse angle SOT ; (ii) arc SRT ; (iii) |BT| 

(b) Find, correct to the nearest cm, the length of the string. (Take \(\pi = \frac{22}{7}\)).

View Answer & Discuss WAEC 1998
891

A surveyor standing at a point X sights a pole Y due east of him and a tower Z of a building on a bearing of 046°. After walking to a point W, a distance of 180m in the South- East direction, he observes the bearing of Z and Y to be 337° and 050° respectively.

(a) Calculate, correct to the nearest metre : (i) |XY| ; (ii) |ZW| 

(b) If N is on XY such that XZ = ZN, find the bearing of Z from N.

View Answer & Discuss WAEC 1998
892

Using a ruler and a pair of compasses only, construct (a) triangle QRT with |QR| = 8cm, |RT| = 6cm and |QT| = 4.5cm.

(b) a quadrilateral QRSP which has a common base QR with \(\Delta\)QRT such that QTP is a straight line, PQ || SR, |QP| = 9cm and |RS| = 4.5cm.

(i) Measure |PS| ; (ii) Find the perpendicular distance between RS and PQ ; (iii) What is QRSP?

View Answer & Discuss WAEC 1998
893

(a) Copy and complete the table of values for the relation \(y = 5 – 7x – 6x^{2}\) for \(-3 \leq x \leq 2\).

x -3 -2 -1 -0.5 0 1 2
y -28   6   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 :

(i) graph of \(y = 5 – 7x – 6x^{2}\) ; (ii) line \(y = 3\) on the same axis.

(c) Use your graph to find the : (i) roots of the equation \(2 – 7x – 6x^{2} = 0\) ; (ii) maximum value of \(y = 5 – 7x – 6x^{2}\).

View Answer & Discuss WAEC 1998
894

(a) A radio which a dealer bought for N6,000.00 and marked to give a profit of 30% was reduced in a sales by 10%. Find : (i) the final sales price ; (ii) the percentage profit.

(b) Solve the equation : \(2^{(2x + 1)} – 9(2^{x}) + 4 = 0\).

View Answer & Discuss WAEC 1998
895

The third term of a Geometric Progression (G.P) is 360 and the sixth term is 1215. Find the 

(a) common ratio;

(b) first term ;

(c) sum of the first four terms.

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896

(a) A number is selected at random from each of the sets {2, 3, 4} and {1, 3, 5}. What is the probability that the sum of the two numbers will be less than 7 but greater than 3?

(b) 

In the diagram, ABCD is a circle. DAE, CBE, ABF and DCF are straight lines. If y + m = 90°, find the value of x.

View Answer & Discuss WAEC 1998
897

The area of a rectangular floor is 13.5m\(^{2}\). One side is 1.5m longer than the other.

(a) Calculate the dimensions of the floor ;

(b) If it costs N250.00 per square metre to carpet the floor and only N2,000.00 is available, what area of the floor can be covered with carpet?

View Answer & Discuss WAEC 1998
898

(a) The value of the expression \(2Ax – Kx^{2}\) is 7 when x = 1 and 4 when x = 2. Find the values of the constants A and K.

(b) Solve the equation \(x^{2} – 3x – 1 = 0\), giving your answers correct to 1 decimal place.

View Answer & Discuss WAEC 1998
899

(a) Given that \(\log_{10} 2 = 0.3010, \log_{10} 7 = 0.8451\) and \(\log_{10} 5 = 0.6990\), evaluate without using logarithm tables:

(i) \(\log_{10} 35\); (ii) \(\log_{10} 2.8\).

(b) Given that \(N^{0.8942} = 2.8\), use your result in (a)(ii) to find the value of N.

View Answer & Discuss WAEC 1998
900

A, B and C are subsets of the universal set U such that : \(U = {0, 1, 2, 3,…, 12}; A = {x : 0 \leq x \leq 7}; B = {4, 6, 8, 10, 12}; C = {1 < y < 8}\), where y is a prime number.

(a) Draw a venn diagram to illustrate the information given above;

(b) Find: (i) \((B \cup C)’\); (ii) \(A’ \cap B \cap C\).

View Answer & Discuss WAEC 1998
901

(a) Copy and complete the following table of values for \(y = 9 \cos x + 5 \sin x\) to one decimal place.

x 30° 60° 90° 120° 150° 180° 210°
y   10.3     -0.2 -5.3   -10.3

(b) Using a scale of 2cm to 30° on the x- axis and 2 cm to 1 unit on the y- axis, draw the graph of \(y = 9 \cos x + 5 \sin x\) for \(0° \leq x \leq 210°\).

(c) Use your graph to solve the equation: (i) \(9\cos x + 5\sin x = 0\); (ii) \(9\cos x+ 5\sin x = 3.5\), correct to the nearest degree.

(d) Find the maximum value of y correct to one decimal place.

 

View Answer & Discuss WAEC 1999
902

(a) A shop owner marked a shirt at a price to enable him to make a gain of 20%. During a special sales period, the shirt was sold at 10% reduction to a customer at N864.00. What was the original cost to the shop owner?

(b) A rectangular lawn of length (x + 5) metres is (x – 2) metres wide. If the diagonal is (x + 6) metres, find ;

(i) the value of x ; (ii) the area of lawn.

View Answer & Discuss WAEC 1999
903

On a graph sheet, using a scale of 2cm to 2 units on both axes, 

(a) Draw the straight line joining points P(-5, 3) and Q(2, 3);

(b) construct the locus L of points equidistant from P and Q;

(c) by construction, locate points R and S on L, such that PRQS forms a rhombus of sides 5cm;

(d) find : (i) coordinates of R and S; (ii) area of the rhombus in cm\(^{2}\).

View Answer & Discuss WAEC 1999