Mathematics for IGCSE & O level - Sets (Section 1 - No. 28)
If A = {1, 2, 3}, then which of the following is a subset of A?
{1, 2, 3}
{1, 2, 4}
{1}
{}
Vysvětlení
A subset contains elements that are all in the original set. The empty set is always a subset