Question

If A = {x : x is a letter of the word SET} and B = {x : x is a letter of the word SETTEE}, then A and B are __________.

• A. null sets
• B. power sets
• C. disjoint sets
• D. equal sets

Answer 1

The correct option is D equal sets

A = {x: x is a letter of the word SET}

$\Rightarrow$ A = {S, E, T}

$\Rightarrow$ n(A) = 3

B = {x: x is a letter of the word SETTEE}

$\Rightarrow$ B = {S, E, T}

$\Rightarrow$ n(B) = 3

As A and B have the same cardinal number and the same elements, A = B

$\therefore$ A and B are equal sets.