Mathematics for IGCSE & O level - Sets (Section 3 - No. 13)
If A = {x | x is a letter in the word 'apple'} and B = {x | x is a letter in the word 'banana'}, then A ∩ B = ?
{a, p}
{a, b, e, n}
{p}
{}
Giải thích
A = {a, p, l, e} and B = {b, a, n}. A ∩ B = {a}