General Mathematics Paper 2,May/June. 2010
 Questions: 1 2 3 4 5 6 7 8 9 10 11 12 13 Main
Weakness/Remedies
Strength

Question 1

A = {2, 4, 6, 8}, B = {2, 3, 7, 9} and C = {x: 3 < x < 9} are subsets of the universal-set
U = {2, 3, 4, 5, 6, 7, 8, 9}. Find
(a)   A n(B'nC');
(b) (AuB) n(BuC).

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Observation

This question was reportedly attempted by majority of the candidates and their performance was described as satisfactory. Many of them lost some marks because they failed to use curly brackets to enclose the elements of the sets. A good number of the candidates were also reported not to have listed the elements of set C hence, were not able to find its complement while others did not separate the elements of a set with comas.

Candidates were expected to list the elements of C i.e. C = {4, 5,6, 7, 8}, obtain the compliments of the sets Band C thus B' = {4,5,6, 8}, C' = {2, 3, 9,}. Using these sets, the following procedures were to be followed:
(a)(B' nC') = { } Hence An (B' n C') = { }. Some candidates were reported to have written { 0 } instead of { } or 0.
(b) (A u B) = { 2, 3,4,6, 7, 8, 9 }, (BuC) = {2, 3, 4,5,6, 7, 8, 9 } Therefore { Au B } n (BuC) = { 2, 3, 4, 6, 7, 8, 9 }.