A = {distinct letters in the word keep}
B = {13}
C = {k, e, p}
D = {4 + 1}
E = {five}
F = {5}

(a) What is the cardinality of each set?
|A| =
3
|B| =
|C| =
|D| =
|E| =
|F| =

(b) Which of the sets are equivalent?
A ↔ C; B ↔ D ↔ E ↔ F
A ↔ C ↔ D; E ↔ F
A ↔ C; D ↔ E ↔ F
A ↔ C ↔ B ↔ D ↔ E ↔ F
A ↔ B; C ↔ D; E ↔ F

(c) Which of the given sets are equal?
A = C = D; E = F
A = C = D = E = F
C = E = F
A = C; B = D = E = F
A = C; D = E = F