Jamb 1981 Mathematics Questions
Question 36:
Multiply x2 + x + 1 by x2 - x + 1
- A X<sup style='font-size: smaller;'>4</sup> - x + x<sup style='font-size: smaller;'>2</sup>
- B X<sup style='font-size: smaller;'>4</sup> - x<sup style='font-size: smaller;'>2</sup> + x<sup style='font-size: smaller;'>2</sup>
- C X<sup style='font-size: smaller;'>4</sup> + x<sup style='font-size: smaller;'>2</sup> + 1
- D X<sup style='font-size: smaller;'>4</sup> + x<sup style='font-size: smaller;'>2</sup>
Question 37:
A baking recipe calls for 2.5kg of sugar and 4.5kg of flour. With this recipe some cakes were baked using 24.5kg of a mixture of sugar and flour. How much sugar was used?
- A 12.25kg
- B 6.75kg
- C 8.75kg
- D 15.75kg
- E 8.25kg
Question 38:
The difference between 4\(\frac{5}{7}\) and 2\(\frac{1}{4}\) greater by
- A \(\frac{23}{28}\)
- B \(\frac{24}{28}\)
- C \(\frac{50}{56}\)
- D \(\frac{27}{28}\)
- E \(\frac{48}{56}\)
Question 39:
What is the size of an exterior angle of a regular pentagon?
- A 36<sup style='font-size: smaller;'>o</sup>
- B 60<sup style='font-size: smaller;'>o</sup>
- C 72<sup style='font-size: smaller;'>o</sup>
- D 120<sup style='font-size: smaller;'>o</sup>
- E 360<sup style='font-size: smaller;'>o</sup>
Question 40:
The sum of the root of a quadratic equation is \(\frac{5}{2}\) and the product of its root is 4. The quadratic equation is
- A X + 8x<sup style='font-size: smaller;'>2</sup> - 5 = 0
- B 2x<sup style='font-size: smaller;'>2</sup> - 5x + 8 = 0
- C 2x<sup style='font-size: smaller;'>2</sup> - 8x + 5 = 0
- D X<sup style='font-size: smaller;'>2</sup> + 8x - 5 = 0