Jamb Mathematics 2011 Past Questions and Answers

Question 21:

• JAMB 2011

A binary operation \(\oplus\) om real numbers is defined by x \(\oplus\) y = xy + x + y for two real numbers x and y. Find the value of 3 \(\oplus\) - \(\frac{2}{3}\).

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

Question 22:

• JAMB 2011

If \(\begin{vmatrix} 2 & 3 \\ 5 & 3x \end{vmatrix}\) = \(\begin{vmatrix} 4 & 1 \\ 3 & 2x \end{vmatrix}\), find the value of x.

A. -6
B. 6
C. -12
D. 12

Question 23:

• JAMB 2011

Evaluate \(\begin{vmatrix} 4 & 2 & -1 \\ 2 & 3 & -1 \\ -1 & 1 & 3 \end{vmatrix}\)

A. 25
B. 45
C. 15
D. 55

Question 24:

• JAMB 2011

The inverse of matrix N = \(\begin{vmatrix} 2 & 3 \\
1 & 4\end{vmatrix}\) is

A. \(\frac{1}{5}\) \(\begin{vmatrix} 2 & 1 \\ 3 & 4\end{vmatrix}\)
B. \(\frac{1}{5}\) \(\begin{vmatrix} 4 & -3 \\ -1 & 2\end{vmatrix}\)
C. \(\frac{1}{5}\) \(\begin{vmatrix} 2 & -1 \\ -3 & 4\end{vmatrix}\)
D. \(\frac{1}{5}\) \(\begin{vmatrix} 4 & 3 \\ 1 & 2\end{vmatrix}\)

Question 25:

• JAMB 2011

What is the size of each interior angle of a 12-sided regular polygon?

A. 120^o
B. 150^o
C. 30^o
D. 180^o