Binary Operations Jamb Mathematics Past Questions
Question 31
If a \(\ast\) b = + \(\sqrt{ab}\), evaluate 2 \(\ast\)(12 \(\ast\) 27)
- A. 12
- B. 9
- C. 6
- D. 2
Question 32
A binary operation \(\oplus\) is defines on the set of all positive integers by a \(\oplus\) b = ab for all positive integers a, b. Which of the following properties does NOT hold?
- A. closure
- B. identity
- C. positive
- D. inverse
Question 33
\(\begin{array}{c|c} \oplus mod 10 & 2 & 4 & 6 & 8 \\ \hline 2 & 4 & 8 & 2 & 6 \\4 & 8 & 6 & 4 & 2\\ 4 & 8 & 6 & 4 & 2\\ 6 & 2 & 4 & 6 & 8\\ 8 & 6 & 2 & 8 & 4\end{array}\)
The multiplication table above has modulo 10 on the set S = (2, 4, 6, 8). Find the inverse of 2
- A. 2
- B. 4
- C. 6
- D. 8
Question 34
A binary operation \(\ast\) is defined on a set of real numbers by x \(\ast\) y = \(x^y\)
for all real values of x and y. If x \(\ast\) 2 = x. Find the possible values of x
- A. 0, 1
- B. 1, 2
- C. 2, 2
- D. 0, 2
Question 35
If the binary operation \(\ast\) is defined by m \(\ast\) n = mn + m + n for any real number m and n, find the identity of the elements under this operation
- A. e = 1
- B. e = -1
- C. e = -2
- D. e = 0
