Binary Operations - Jamb Mathematics Past Questions and Answers

Question 16:

• JAMB 1995

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

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

Question 17:

• 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 18:

• JAMB 1995

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

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

Question 19:

• JAMB 1997

Two binary operations \(\ast\) and \(\oplus\) are defines as m \(\ast\) n = mn - n - 1 and m \(\oplus\) n = mn + n - 2 for all real numbers m, n.
Find the value of 3 \(\oplus\) (4 \(\ast\) 50)

A. 60
B. 57
C. 54
D. 42

Question 20:

• JAMB 1997

If X \(\ast\) Y = X + Y - XY, find x when (x \(\ast\) 2) + (x \(\ast\) 3) = 68

A. 24
B. 22
C. -12
D. -21