Paper 1  Objectives  47 Questions
JAMB Exam
Year: 1981
Level: SHS
Time:
Type: Question Paper
Answers provided
No description provided
This paper is yet to be rated
These are the best study techniques and methods that get higher grades in any school tests or exams.
Try studying past questions since it's a sure way to better grades in any subject at school and beyond.
Past questions are effective for revisions for all tests including WAEC, BECE, SAT, TOEFL, GCSE, IELTS
#  Question  Ans 

1. 
Suppose x varies inversely as y, y varies directly as the square of t and x = 1, when t = 3. Find x when t = \(\frac{1}{3}\). A. 81 B. 27 C. \(\frac{1}{9}\) D. \(\frac{1}{27}\) E. \(\frac{1}{81}\)
Show Content
Detailed Solution\(x \propto \frac{1}{y}\)\(x = \frac{k}{y}\) \(y \propto t^{2}\) \(y = ct^{2}\) k and c are constants. \(x = \frac{k}{ct^{2}}\) Let \(\frac{k}{c} = d\) (a constant) \(x = \frac{d}{t^{2}}\) \(1 = \frac{d}{3^{2}} \implies d = 9\) \(\therefore x = \frac{9}{t^{2}}\) \(x = 9 \div (\frac{1}{3})^{2} \) = \( 9 \div \frac{1}{9} = 9 \times 9 = 81\) 

2. 
If sine x equals cosine x, what is x in radians? A. \(\frac{\pi}{2}\) B. \(\frac{\pi}{3}\) C. \(\frac{\pi}{4}\) D. \(\frac{\pi}{6}\) E. \(\frac{\pi}{12}\)
Show Content
Detailed Solution\(\sin x = \cos x\)\(\implies x = 45°\) In radians, \(x = \frac{\pi}{4}\). 

3. 
The ratio of the price of a loaf of bread to the price of a packet of sugar in 1975 was r : t. In 1980, the price of a loaf went up by 25% and that of a packet of sugar went up by 10%. Their new ratio is now A. 40r:50t B. 44r : 50t C. 50r : 44t D. 44r:55t E. 55r:44t
Show Content
Detailed SolutionRatio of bread to sugar = r:t25% increase in bread = \(\frac{125r}{100}\) 10% increase in sugar = \(\frac{100t}{100}\) New ratio = \(\frac{125r}{100}\):\(\frac{110t}{100}\) = 25r:22t = 50r:44t 

4. 
Find a twodigit number such that three times the tens digit is 2 less than twice the units digit and twice the number is 20 greater than the number obtained by reversing the digits A. 24 B. 42 C. 74 D. 47 E. 72
Show Content
Detailed SolutionLet the tens digits of the number be x and the unit digit be y3x = 2y  2 3x  2y = 2.......(i) If the digits are interchanged, the tens digit becomes y, the unit digit becomes x. Hence 2(10x + y) = 10y + x + 20 (20x + 2y)  (10y + x) = 20 19x  8y = 20.....(ii) Multiply eqn.(i) by 8 and eqn.(ii) by 2 24x  16y = 16......(iii) 38x  16y = 40........(iv) eqn(iv)  eqn(iii) 14x = 56 x = 4 Sub. for x = 4 in eqn(i) 3(4)  

5. 
Find the value of x satisfying \(\frac{x}{2}\)  \(\frac{1}{3}\) < \(\frac{2x}{5}\) + \(\frac{1}{6}\) A. x < 5 B. x < 7\(\frac{1}{2}\) C. x > 5 D. x > 7\(\frac{1}{2}\)
Show Content
Detailed Solution\(\frac{x}{2}  \frac{1}{3} < \frac{2x}{5} + \frac{1}{6}\)\(\frac{x}{2}  \frac{2x}{5} < \frac{1}{6} + \frac{1}{3}\) \(\frac{x}{10} < \frac{1}{2}\) \(2x < 10 \implies x < 5\) 

6. 
A group of 14 children children received the following scores in a reading test: 35, 35, 26, 26, 26, 29, 29, 29, 12, 25, 25, 25, 25, 17. What was the median score? A. 29 B. 26 C. 24 D. 25 E. 23
Show Content
Detailed SolutionArranging the scores in ascending order:12, 17, 25, 25, 25, 25, 26, 26, 26, 29, 29, 29, 35, 35. The median is the average of the 7th and 8th marks. = \(\frac{26 + 26}{2} = 26\) 

7. 
Which of the following fractions is less than onethird? A. \(\frac{22}{63}\) B. \(\frac{4}{11}\) C. \(\frac{15}{46}\) D. \(\frac{33}{98}\) E. \(\frac{122}{303}\)
Show Content
Detailed SolutionAll others are greater than 0.333 when converted to their fractions except \(\frac{15}{46}\) 

8. 
A cuboid has a diagonal of length 9cm and a square base of side 4cm. What is its height? A. 9cm B. \(\sqrt{65}\)cm C. \(4\sqrt{2}\)cm D. 7cm E. 6.5cm
Show Content
Detailed SolutionGiven a cuboid, the diagonal cuts a face of the cuboid into 2 rightangled triangles.Hence, using the Pythagoras theorem, we have \(9^{2} = 4^{2} + x^{2}\) \(81 = 16 + x^{2}\) \(x^{2} = 81  16 = 65\) \(\therefore x = \sqrt{65} cm\) 

9. 
Evaluate correct to 4 decimal places 827.51 x 0.015 A. 8.8415 B. 12.4127 C. 124.1265 D. 12.4120 E. 114.1265
Show Content
Detailed Solution827.51 x 0.015By normal multiplication or use of four figure table, 827.51 x 0.015 = 12.4127 (to 4 decimal places). 

10. 
What is the area between two concentric circles of diameters 26cm and 20cm? A. 100\(\pi\) B. 169\(\pi\) C. 69\(\pi\) D. 9\(\pi\) E. 269\(\pi\)
Show Content
Detailed SolutionArea of circle 1 with diameter 26cm:\(\pi r^{2} = \pi \times (\frac{26}{2})^{2} \) = \(169 \pi cm^{2}\) Area of circle 2 with diameter 20 cm: \(\pi R^{2} = \pi \times (\frac{20}{2})^{2}\) = \(100 \pi cm^{2}\) Area between the two circles = \((169  100) \pi cm^{2}\) = \(69 \pi cm^{2}\) 
Preview displays only 10 out of the 47 Questions