Waec Mathematics 1991 Past Questions and Answers

Question 31:

• WAEC 1991

P={2, 1,3, 9, 1/2}; Q = {1,21/2,3, 7} and R = {5, 4, 21/2}. Find P∪Q∪R

A. (2¹/₂)
B. (1, 9)
C. (1, 2, 3, 4, 5, 6, 7)
D. (5, 4, 2¹/₂)
E. (¹/₂, 1, 2, 2¹/₂, 3, 4, 5, 7, 9)

Question 32:

• WAEC 1991

P = {2, 1,3, 9, 1/2}; Q = {1,21/2,3, 7} and R = {5, 4, 21/2}. Find P∩Q∩R

A. (2¹/₂)
B. ∅
C. (1, 3, 7)
D. (4)
E. (5,7,9)

Question 33:

• WAEC 1991

In a class of 80 students, every student had to study Economics or Geography or both Economics and Geography.

lf 65 students studied Economics and 50 studied Geography, how many studied both subjects?

A. 15
B. 30
C. 35
D. 45
E. 50

Question 34:

• WAEC 1991

Which of the following is not a measure of dispersion?

A. Mode
B. Mean deviation
C. Range
D. Interquartile range
E. Standard deviation

Question 35:

• WAEC 1991

The mean of 30 observations recorded in an experiment is 5. lf the observed largest value of 34 is deleted, find the mean of the remaining observations

A. 5
B. 4
C. 3.9
D. 3.4
E. 3.0