Question

1(a) mu = {1,2,3,4,5,6,7,8,9,10} is the universal set and its subsets A, B and C are defined as follows: A = {x : x is a multiple of 2}, B = {x : x is a multiple of 3}, C = {x : x is a factor of 6}. Find A' n B' n C'. (b) A pack of five tickets cost $80.00. The retail price for one ticket is $18.50. If a group of five persons paid for five tickets as a group, find the amount saved by each person.

Accepted Answer

(a) mu = {1,2,3,4,5,6,7,8,9,10}. A = {2,4,6,8,10}, B = {3,6,9}, C = {1,2,3,6}. Then A' = {1,3,5,7,9}, B' = {1,2,4,5,7,8,10}, C' = {4,5,7,8,9,10}. Therefore A' n B' n C' = {5,7} (the elements present in the universal set that are found in all three complement sets).
(b) A premiere ticket bought individually would cost = $18.50 x 5 = $92.50. At bulk purchase, five tickets would cost $80.00. Therefore, cost of one ticket at bulk purchase = Bulk purchase price / No of tickets in bulk = $80/5 = $16.00. Amount saved by each person = $18.50 - $16.00 = $2.50.

WAEC Mathematics 2020 Theory — Question 1

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