Jamb Mathematics 1998 Past Questions and Answers

Question 16:

• JAMB 1998

The sum of the first three terms of a geometric progression is half its sum to infinity. Find the positive common ratio of the progression.

A. \(\frac{1}{4}\)
B. \(\sqrt{\frac{3}{2}}\)
C. \(\frac{1}{\sqrt{3}}\)
D. \(\frac{1}{\sqrt{2}}\)

Question 17:

• JAMB 1998

The identity element with respect to the multiplication shown in the diagram below is \(\begin{array}{c|c} \otimes & p & p & r & s \\ \hline p & r & p & r & p
\\ q & p & q & r & s\\ r & r & r & r & r\\ s & q & s & r & q\end{array}\)

A. P
B. Q
C. R
D. S

Question 18:

• JAMB 1998

The binary operation \(\oplus\) is defined by x \(\ast\) y = xy - y - x for all real values x and y. If x \(\ast\) 3 = 2\(\ast\), find x

A. -1
B. 4
C. 1
D. 5

Question 19:

• JAMB 1998

The determinant of matrix \(\begin{pmatrix} x & 1 & 0 \\ 1-x & 2 & 3 \\ 1 & 1+x & 4\end{pmatrix}\) in terms of x is

A. -3x² - 17
B. -3x² + 9x - 1
C. 3x² + 17
D. 3x² - 9x + 5

Question 20:

• JAMB 1998

Let = \(\begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}\) p = \(\begin{pmatrix} 2 & 3 \\ 4 & 5 \end{pmatrix}\) Q = \(\begin{pmatrix} u & 4+u \\ -2v & v \end{pmatrix}\) be 2 x 2 matrices such that PQ = 1. Find (u, v)

A. (-\(\frac{5}{2}\) - 1)
B. (-\(\frac{5}{2}\) - \(\frac{3}{2}\))
C. (-\(\frac{5}{6}\) - 1)
D. (\(\frac{5}{2}\) - \(\frac{3}{2}\))