Mathematics 2024 Objective — Question 1
Express 367900 in standard form.
- A. 3.679 x 10^4
- B. 3.679 x 10^5Correct
- C. 3.679 x 10^6
- D. 3.679 x 10^7
- E. 3.679 x 10^8
Explanation
367900 = 3.679 x 100000 = 3.679 x 10^5.
All 120 questions from the Basic Education Certificate Examination (Junior WAEC) (BECE) Mathematics 2024 Objective paper, with the correct answer and a full explanation for each. Free, no signup needed.
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Express 367900 in standard form.
367900 = 3.679 x 100000 = 3.679 x 10^5.
Express 0.0007823 in standard form.
Move the decimal 4 places right: 7.823 x 10^-4.
Simplify (0.012 x 0.00009) / 0.06, correct to one significant figure.
0.012 x 0.00009 = 0.00000108; divided by 0.06 = 0.000018 = 1.8 x 10^-5.
Simplify 2 1/2 + 5.
2 1/2 + 5 = 5/2 + 5 = 15/2.
Simplify 5 2/3 ÷ 3 1/4.
17/3 - 13/4 = (68 - 39)/12 = 29/12, which is option A.
Simplify 2 3/2 x 1 3/5 ÷ 1 2/5.
2 3/2 = 7/2; 7/2 x 8/5 x 5/7 = 4.
Simplify 5 1/4 - (1 2/3 - 1/2).
1 2/3 - 1/2 = 7/6; 21/4 - 7/6 = 63/12 - 14/12 = 49/12 = 4 1/12.
Convert 1.625 into a mixed fraction.
0.625 = 5/8, so 1.625 = 1 5/8.
What is the square of 27?
27 x 27 = 729.
Find the smallest number by which 60 must be multiplied to be a perfect square.
60 = 2 x 2 x 3 x 5; multiply by 3 x 5 = 15 to pair all factors.
Divide the L.C.M. of 36, 72 and 144 by their H.C.F.
LCM = 144, HCF = 36; 144 ÷ 36 = 4.
Find the H.C.F. of 18, 40 and 48.
18 = 2x3x3, 40 = 2x2x2x5, 48 = 2x2x2x2x3; common factor is 2.
The H.C.F. of 48, x and 88 is 8. What is the value of x?
x must be a multiple of 8 only: 56 = 8 x 7, and HCF(48, 56, 88) = 8.
Express 0.025 in the form a/b in its lowest form.
0.025 = 25/1000 = 1/40.
Express 15 as a percentage of 20.
15/20 x 100 = 75%.
Find 7.5% of 4kg 300g, correct to 3 significant figures.
4 kg 300 g = 4300 g; 7.5% of 4300 = 322.5 = 323 g (3 s.f.).
Express 68 as a binary number.
68 = 64 + 4 = 1000100₂.
Express 144 as a product of prime factors in index form.
144 = 16 x 9 = 2^4 x 3^2.
Convert 111₂ to base 10.
1x4 + 1x2 + 1 = 7.
If the simple interest on a certain amount for 2 years at 5% per annum is ₦2,400.00, find the principal.
P = (100 x I)/(R x T) = 240000/10 = ₦24,000.
Subtract 9.65 from 42.5.
42.50 - 9.65 = 32.85.
Find the simple interest on ₦15,000.00 deposited for 2 1/2 years at 5 1/2 % per annum.
15000 x 5.5 x 2.5 / 100 = ₦2062.50.
Felix bought a car at the rate of ₦3,088,144.00. He made the cash payment of 32% and paid the remaining through bank transfer. How much was paid through transfer?
Transfer = 68% of 3,088,144 = ₦2,099,937.92.
Estimate the sum of the following amounts; ₦10.50, ₦5.85, ₦125.10, ₦16.20, ₦15.20.
Round each to the nearest naira: 11 + 6 + 125 + 16 + 15 = ₦173.
What is the value of ∠QPR in the figure below?
The construction marks show a 60° angle that has been bisected, giving 30°.
The interior angle of a regular polygon is 165°. How many sides does the polygon have?
Exterior angle = 180 - 165 = 15°; n = 360 ÷ 15 = 24.
If M varies inversely as the square of N, find the formula connecting M and N given that M = 2 and N = 1/2.
M = k/N²; 2 = k/(1/4) so k = 1/2; M = 1/(2N²).
Which of the following angles cannot be constructed using a ruler and a pair of compasses only?
30°, 60°, 90° and 120° come from 60° and bisection; 140° cannot.
Find the sum of the interior angles of a polygon which has 10 sides.
(n - 2) x 180 = 8 x 180 = 1,440°.
How many triangles can be cut out of a pentagon?
From one vertex, (n - 2) = 3 triangles.
Find the area of a circle with diameter 42 cm. (Take π = 22/7).
r = 21; A = 22/7 x 21 x 21 = 1,386 cm².
Find the value of y in the diagram below, correct to one decimal place.
y is adjacent to 50°, hypotenuse 25: y = 25 cos 50° = 16.1 cm.
Calculate the radius of a circle whose circumference is 21 cm. Leave your answer in term of π.
2πr = 21 so r = 21/(2π) cm.
Find the volume of a cylinder whose base radius is 3 1/2 cm and height 10 cm. (Take π = 22/7).
V = 22/7 x 3.5 x 3.5 x 10 = 385 cm³.
Find the value of x in the diagram below:
x² = 3² + 4² = 25, so x = 5.
The area of a circle is 154 cm². Find the perimeter of the circle. (Take π = 22/7).
πr² = 154 gives r = 7; perimeter = 2 x 22/7 x 7 = 44 cm.
Find the perimeter of the shape below:
x² = 15² + 20² = 625 so x = 25; perimeter = 15 + 20 + 25 = 60 cm.
Calculate the value of x in the figure below, correct to one decimal place.
x = 10 sin 45° = 7.07 = 7.1 m.
Find the area of the shape below:
ED = CF = 3 cm (3-4-5), so EF = 18 cm; area = (12 + 18)/2 x 4 = 60 cm².
Calculate the value of x in the figure below, correct to two decimal places.
x = 15 ÷ tan 50° = 12.59 m.
Calculate the area of a parallelogram whose base is 15 cm and height 2.5 cm.
Area = base x height = 15 x 2.5 = 37.5 cm².
Find the volume of a cuboid 25cm long, 15cm wide and 10cm high.
25 x 15 x 10 = 3,750 cm³.
Calculate the volume of a cone whose height is 14/3 cm and base radius 3/2 cm. (Take π = 22/7).
V = 1/3 x 22/7 x 3/2 x 3/2 x 14/3 = 11 cm³.
In the figure below, find the height of the parallelogram ABCD if its area is 28 cm².
Height = area ÷ base = 28 ÷ 7 = 4 cm.
The bearing of X and Y is 145°. What is the bearing of Y from X?
Taking 145° as the bearing of X from Y, the back bearing is 145° + 180° = 325°.
Convert the compass bearing S83° W to a three-figured bearing.
180° + 83° = 263°.
State the three-figured bearing of X from Y in the figured below:
Bearing of Y from X = 360° - 140° = 220°; back bearing of X from Y = 220° - 180° = 040°.
Find the value of x in the diagram below:
x is opposite the 30° angle: x = 16 sin 30° = 8 m.
Find the value of x in the diagram below:
(x + 2) + (2x + 23) + (3x + 5) = 180; 6x + 30 = 180; x = 25.
The linear scale factor of two similar shapes is 3:4. If the area of the smaller shape is 81cm², find the area of the bigger one.
Area scale factor 9:16; 81 x 16/9 = 144 cm².
A man bought an article for ₦6,800.00 and received ₦420.00 as commission. Calculate the percentage of the commission, correct to one decimal place.
420/6800 x 100 = 6.18 = 6.2%.
The area and a diagonal of a rhombus are 360cm² and 24 cm respectively. What is the length of the other diagonal?
Area = (d1 x d2)/2; 360 = 24d/2; d = 30 cm.
The volume scale factor of two similar solids is 64: 125. Determine their area scale factor.
Linear 4:5, so area 16:25.
The linear scale factor of two similar shapes is 3:7. Determine their volume scale factor.
3³ : 7³ = 27 : 343.
The linear scale factor of two similar shapes is 4:5. Find their area scale factor.
4² : 5² = 16 : 25.
The area scale factor of two solid shapes are 4:9. If the volume of the bigger shape is 270cm³, what is the volume of the smaller one?
Linear 2:3, volume 8:27; 270 x 8/27 = 80 cm³.
PQRS is a parallelogram such that /PQ/ = 15cm, /QR/ = 18 cm and ∠PQR = 30°. Determine the area of the parallelogram.
Area = 15 x 18 x sin 30° = 135 cm².
Find the area of a circle whose radius is 7cm. (Take π = 22/7).
22/7 x 7 x 7 = 154 cm².
Find the value of y° in the diagram below:
Angles on a straight line: 2y + 5y + y = 180; 8y = 180; y = 22.5.
Calculate the area of the shaded portion in the figure below: (Take π = 22/7).
Rectangle = 20 x 15 = 300 cm²; semicircle (diameter 15) = 1/2 x 22/7 x 7.5² = 88.4 cm²; shaded = 300 - 88.4 = 211.6, about 212 cm².
If 3x × 15 = 90, find the value of x.
45x = 90; x = 2.
Solve for x if 3(4x - 8) + 12 = 0.
12x - 24 + 12 = 0; 12x = 12; x = 1.
Mr. Abraka thought of a number and added 3 times the number. If the result is 2 times the number plus 4, what is the number?
n + 3n = 2n + 4; 2n = 4; n = 2.
Solve the equation 1/m = 4/5.
m = 5/4 = 1 1/4.
Factorise 2m² - 8n².
2(m² - 4n²) = 2(m - 2n)(m + 2n).
Factorise 25x² - y².
Difference of two squares: (5x)² - y² = (5x - y)(5x + y).
Factorise x² + 4x - 12.
Factors of -12 that add to 4: 6 and -2.
Express 3a/5 + 2b/3 as a single fraction.
LCD 15: (9a + 10b)/15.
Solve the equation (a - 4)/5 = 2 - a/2.
Multiply by 10: 2(a - 4) = 20 - 5a; 7a = 28; a = 4.
Simplify (n - 1)/6 + (n + 1)/8.
(4(n - 1) + 3(n + 1))/24 = (7n - 1)/24.
If 2((4x - 1)/2) = 9((x + 1)/4), find the value of x.
4x - 1 = 9(x + 1)/4; 16x - 4 = 9x + 9; 7x = 13; x = 1 6/7.
Solve the equation 8/(4(x - 2)) = 1/10.
80 = 4(x - 2); x - 2 = 20; x = 22.
Solve for x if 28x + 3/5 = x + 3/2.
27x = 3/2 - 3/5 = 9/10; x = 1/30.
Factorise 3x² - y² - 3xy + xy.
3x² - 3xy + xy - y² = 3x(x - y) + y(x - y) = (x - y)(3x + y).
Expand and simplify (5x - 3y)(2x + 4y).
10x² + 20xy - 6xy - 12y² = 10x² + 14xy - 12y².
Olu thought of a number and subtracted 2 from it. He divided 32 by the result. If his answer is 4, find the number.
32/(n - 2) = 4; n - 2 = 8; n = 10.
Factorise a² - 6a - 7.
Factors of -7 that add to -6: 1 and -7.
Factorise a² + 9a + 8.
Factors of 8 that add to 9: 1 and 8.
Solve 4 + 4x ≥ 5x + 8.
4 - 8 ≥ 5x - 4x; -4 ≥ x; x ≤ -4.
Which of the following line graphs represents the solution of 2x > 6x + 8?
2x - 6x > 8; -4x > 8; x < -2 (divide by -4 reverses the sign): open circle at -2 with arrow to the left.
The sum of two numbers is 120. If one of the numbers is -75, find the other number.
120 - (-75) = 195.
Which of the following is/are not method(s) of solving simultaneous linear equations? I. Elimination II. Completing the square III. Graphical IV. Substitution V. Use of formula
Completing the square and use of formula are for quadratic equations.
Multiply a number by 5, subtract 15 from the result. If the result is 50, find the number.
5n - 15 = 50; 5n = 65; n = 13.
Expand (y - 4)².
(y - 4)(y - 4) = y² - 8y + 16.
Simplify 8x + 3(2y - x).
8x + 6y - 3x = 5x + 6y.
Solve x + 8 = 12.
x = 12 - 8 = 4.
If 7 is added to a number x and the result is greater than 15, find the range of the number.
x + 7 > 15; x > 8.
The inequality represented on the line graph below is ____.
Closed circle at -8 with the arrow to the right: x ≥ -8.
Find the value of x/(z + y) when x = 4, y = -6 and z = 8.
4/(8 - 6) = 4/2 = 2.
Solve the equation 1/(9x + 5) + 1/4 = 0.
1/(9x + 5) = -1/4; 9x + 5 = -4; x = -1.
Solve the following equations simultaneously; 2x + 3y = 4, 6x - y = 2.
y = 6x - 2; 2x + 18x - 6 = 4; x = 1/2, y = 1.
Simplify 2/q - 3/r.
(2r - 3q)/(qr).
Solve 6/(x - 4) = 1/2.
6/(x - 4) = -1/2 gives x - 4 = -12, so x = -8, which is option A.
Simplify m/(3t) - 2n/(4p).
LCD 12tp: (4pm - 6nt)/(12tp) = (2pm - 3nt)/(6tp).
When twice a certain number is subtracted from 13, the result is less than or equal to 5. Find the range of values of the number.
13 - 2x ≤ 5; -2x ≤ -8; x ≥ 4.
Given that x varies inversely as the square of y and varies directly as z. If x = 4, y = 1, z = 1. Find x if y = 3, z = 2.
x = kz/y²; 4 = k(1)/1 so k = 4; x = 4 x 2/9 = 8/9.
If A varies directly as B, when A = 10 and B = 5. Find the value of A when B = 16.
A = kB; k = 2; A = 2 x 16 = 32.
Which of the options below describes a direct variation?
A direct variation has the form y = kx.
y varies directly as x. If y = 10 when x = 5, find the constant of proportionality.
k = y/x = 10/5 = 2.
Use the relationship below to answer the next three questions. Find the missing number (?) in the relationship.
In each figure the top number is the product of the square roots of the two bottom numbers (e.g. √81 x √9 = 9 x 3 = 27). So ? = √9 x √16 = 3 x 4 = 12.
Find the missing number (?) in the relationship.
12 = √144 x √? = 12 x √?; √? = 1; ? = 1.
Find the missing number (?) in the relationship.
90 = √? x √81 = √? x 9; √? = 10; ? = 100.
Find the range of the following set of numbers; 224, 139, 409, 306, 221, 401.
Range = 409 - 139 = 270.
The number represented by the tally 卌 卌 IIII is ____.
5 + 5 + 4 = 14.
If a coin is tossed twice, what is the probability of getting a head and a tail?
Outcomes HH, HT, TH, TT; HT or TH = 2/4 = 1/2.
Find the sum of the median and the range of the following set of numbers; 1, 4, 2, 5, 3.
Ordered 1, 2, 3, 4, 5: median = 3, range = 4; sum = 7.
Find the mode of the following set of numbers; 7, 7, 15, 12, 9, 5, 1, 7, 5, 12.
7 appears three times, more than any other number.
The graphical representation of statistical data in block form joined together is ____.
A histogram has adjacent blocks joined together.
The mean of the following numbers 8, 12, 15, x, 9 is 12. Find the value of x.
Sum = 5 x 12 = 60; 8 + 12 + 15 + 9 = 44; x = 16.
Find the mean of the following set of numbers; 16, 13, 15, 18, 27, 30, correct to two decimal places.
Sum = 119; 119 ÷ 6 = 19.83.
Find the range of the following set of numbers; 101, 322, 223, 154, 132, 116.
Range = 322 - 101 = 221.
In a set of 18 scores arranged in ascending order, the 9th score is 4 more than the 10th score. If the 10th score is 12, find the median score.
9th score = 12 + 4 = 16; median = (9th + 10th)/2 = (16 + 12)/2 = 14.
Use the information below to answer the next two questions. Everton and Chelsea played 20 matches each and their average goals scored are 8.5 and 10.5 respectively. What is the total goal scored by both clubs?
Everton: 20 x 8.5 = 170; Chelsea: 20 x 10.5 = 210; total = 380.
Determine the mean goals of both clubs.
Mean = (8.5 + 10.5)/2 = 9.5.
The pie chart below shows the weekly sales of a motor dealer. Use the chart to answer the next three questions. What fraction of the cars were Honda?
Honda = 90° (from the figure); 90/360 = 1/4.
What percentage of the cars were Nissan, correct to the nearest whole number?
120/360 x 100 = 33.3 = 33%.
Calculate the sectorial angle of Toyota in a week.
360 - (120 + 50 + 90) = 100°.
A box contains six red balls and four blue balls. If a ball is selected at random, what is the probability of selecting a blue ball?
4/10 = 2/5.
If the dice is rolled once, what is the probability of obtaining the number 10?
A dice has no 10, so the probability is 0.
If a dice is cast, what is the probability of getting an even number?
Even numbers 2, 4, 6: 3/6 = 1/2.
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