Question

If S and T are two sets such that S has 21 elements, T has 32 elements, and S ∩ T has 11 elements, how many elements does S ∪ T have?​

Answer 1

$\huge\underline\mathfrak\pink{♡Answer♡}$

We know that

n(S) = 21

n(T) = 32

n(S ∩ T) = 11

It can be written as

n (S ∪ T) = n (S) + n (T) – n (S ∩ T)

Substituting the values

n (S ∪ T) = 21 + 32 – 11

So we get

n (S ∪ T)= 42

Therefore,

the set (S ∪ T) has 42 elements.

Answer 2

Answer:

➡We know that

n(S) = 21

n(T) = 32

n(S ∩ T) = 11

✔It can be written as

n (S ∪ T) = n (S) + n (T) – n (S ∩ T)

➡Substituting the values

n (S ∪ T) = 21 + 32 – 11

So we get

n (S ∪ T)= 42

Therefore,

✔The set (S ∪ T) has 42 elements.