Q3 of 71 Page 23

If X = {x : x = 2n, x ≤ 20 and } and Y = {x : x = 4n, x ≤ 20 and }

Find (i) X ∪ Y (ii) X ∩ Y

X = {x : x = 2n, x ≤ 20 and n ∈}


X is twice of a natural number(n ∈ N) and less than or equal to 20.


∴ X = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20}


Y = {x : x = 4n, x ≤ 20 and n ∈ }


Y is 4 times a positive whole number(n ∈ W) and less than equal to 20.


∴ Y = {0, 4, 8, 12, 16, 20}


∴ X ∪ Y = {0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20} [elements that are present in either X or Y]


∴ X ∩ Y = {4, 8, 12, 16, 20} [elements that are present in both X and Y]


More from this chapter

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1

Find A ∪ B and A ∩ B for the following sets.

i. A = {0, 1, 2, 4, 6} and B = {−3, −1, 0, 2, 4, 5}


ii. A = {2, 4, 6, 8} and B = Φ


iii. and B = {x : x is a prime number less than 11}


iv. and

2

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State which of the following sets are disjoint

i. A = {2, 4, 6, 8}; B = {x : x is an even number < 10, }


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iii. P = {x : x is a prime < 15}


Q = {x : x is a multiple of 2 and x < 16}


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