Jamb Mathematics 1995 Past Questions and Answers

Question 66:

• JAMB 1995

Which of the following binary operations is cumulative on the set of integers?

A. A \(\ast\) b = a + 2b
B. A \(\ast\) b = a + b - ab
C. A \(\ast\) b = a² + b
D. A \(\ast\) b = \(\frac{a(b + 1)}{2}\)

Question 67:

• JAMB 1995

If a \(\ast\) b = + \(\sqrt{ab}\), evaluate 2 \(\ast\)(12 \(\ast\) 27)

A. 12
B. 9
C. 6
D. 2

Question 68:

• JAMB 1995

Find the sum to infinity of the following sequence \(1, \frac{9}{10}, (\frac{9}{10})^{2}, (\frac{9}{10})^{3}\)

A. \(\frac{1}{10}\)
B. \(\frac{9}{10}\)
C. \(\frac{10}{9}\)
D. 10

Question 69:

• JAMB 1995

\(\begin{vmatrix} -2 & 1 & 1 \\ 2 & 1 & k \\1 & 3 & -1 \end{vmatrix}\) = 23

A. 1
B. 2
C. 3
D. 4

Question 70:

• JAMB 1995

If x = \(\begin{pmatrix} 1 & 2 \\ 0 & 3 \end{pmatrix}\) and y = \(\begin{pmatrix} 2 & 1 \\ 4 & 3 \end{pmatrix}\). Find xy.

A. \(\begin{pmatrix} 10 & 7 \\ 12 & 9 \end{pmatrix}\)
B. \(\begin{pmatrix} 2 & 7 \\ 4 & 17 \end{pmatrix}\)
C. \(\begin{pmatrix} 10 & 4 \\ 4 & 6 \end{pmatrix}\)
D. \(\begin{pmatrix} 4 & 3 \\ 10 & 9 \end{pmatrix}\)