Jamb Mathematics 2008 Past Questions and Answers

Question 21:

• JAMB 2008

A binary operation * is defined on the set of positive integers is such x*y = 2x-3y+2 for all positive integers x and y. The binary operation is

A. Commutative and close on the set of positive integers
B. Neither commutative nor closed on the set of ppositive integers
C. Commutative but not closed on the set of positive integers
D. Not cummutative but closed on the set of positive integers

Question 22:

• JAMB 2008

A binary operation on the real set of numbers excluding -1 is such that for all m, n ∈ R, mΔn = m+n+mn. Find the identity element of the operation.

A. 1
B. Zero
C. -¹/₂
D. -1

Question 23:

• JAMB 2008

In the diagram above, PQ//RS. The size of the angle marked x is

A. 100^o
B. 80^o
C. 50^o
D. 30^o

Question 24:

• JAMB 2008

Find the exterior angle of a 12 sided regular polygon

A. 12^o
B. 24^o
C. 25^o
D. 30^o

Question 25:

• JAMB 2008

In the diagram above ∠ OPQ is

A. 90^o
B. 53^o
C. 36^o
D. 26^o