Jamb 1979 Mathematics Questions
Question 21:
x is directly proportional to y and inversely proportional to z. If x = 9 when y = 24 and z = 8, what is the value of x when y = 5 and z = 6?
- A \(\frac{5}{6}\)
- B 11
- C 3\(\frac{3}{5}\)
- D 2\(\frac{1}{2}\)
- E 1\(\frac{1}{5}\)
Question 22:
The solution of the equation x2 - 2x = 8 is
- A X = 0 or 2
- B X = -2 or 4
- C X = 2
- D X = -4
- E X = 2 or 4
Question 23:
A trader goes to Ghana for y days with y cedis. For the first x days, he spends X cedis per day. The amount he has to spend per day for the rest of his stay is
- A \(\frac{y(y - x)}{y - x}\) cedis
- B \(\frac{Yy - Xx)}{y - x}\) cedis
- C \(\frac{Y - Xy)}{y - x}\) cedis
- D \(\frac{Y - X}{y - x}\) cedis
- E \(\frac{Y - Xx}{y - x}\) cedis
Question 24:
Multiply (3x + 5y + 4z) by (2x - 3y + z)
- A 6x<sup style='font-size: smaller;'>2</sup> + xy - 15y<sup style='font-size: smaller;'>2</sup> + 4z<sup style='font-size: smaller;'>2</sup> + 11xz - 7yz
- B 6x<sup style='font-size: smaller;'>2</sup> + 3xy - 15y<sup style='font-size: smaller;'>2</sup> + 4z<sup style='font-size: smaller;'>2</sup>
- C 6x<sup style='font-size: smaller;'>2</sup> + 3xy - y<sup style='font-size: smaller;'>2</sup> + 4z<sup style='font-size: smaller;'>2</sup>
- D 6x<sup style='font-size: smaller;'>2</sup> + 3xy - 15y + z<sup style='font-size: smaller;'>2</sup>
Question 25:
A square of cardboard is taped at the perimeter by a piece of ribbon 20cm long. What is the area of the board?
- A 20sq.cm
- B 100sq.cm
- C 25sq.cm
- D 16sq.cm
- E 36sq.cm