If U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, A = {1, 2, 3, 5}, B = {2, 4, 6, 7} and C = {2, 3, 4, 8}. Then (B ∪ C)′ is ______.

#### Solution

If U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, A = {1, 2, 3, 5}, B = {2, 4, 6, 7} and C = {2, 3, 4, 8}. Then (B ∪ C)′ is **{1, 5, 9, 10}**.

**Explanation:**

**Given:** U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

A = {1, 2, 3, 5}, B = {2, 4, 6, 7}

And C = {2, 3, 4, 8}

**To find:** (B ∪ C)′ and (C – A)′

**Formula used:**

The** union** of two sets is a set containing all elements that are in both sets.

**For example:** {1, 2, 3} ∪ {2, 4} = {1, 2, 3, 4}

The difference (subtraction) is defined as: The set A – B consists of elements that are in A but not in B.

**For example:** if A = {1, 2, 3} and B = {3, 5}, then A−B = {1, 2}

B = {2, 4, 6, 7} and C = {2, 3, 4, 8}

B ∪ C = {2, 3, 4, 6, 7, 8}

(B ∪ C)’ = U – (B ∪ C)

= {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} – {2, 3, 4, 6, 7, 8}

= {1, 5, 9, 10}