Question

Give one example for integers a,b and c such thata≠b≠c, but a÷(b÷c)= (a÷b)÷c.​

Answer 1

let A={x,y,z}B={a,b,c}andC={m,n,o}

Such that

A∈B⟹B={a,b,c,x,y,z} and

B∈C⟹C={a,b,c,x,y,z,m,n,o}

As such A∈C.

but watch! if A is an empty set i.e A={}

then C={a,b,c,m,n,o}

⟹A∉C.

Else for three sets A, B, and C such that A ϵ B, B ϵ C, and A ∉ C, A must be 0 or {} i.e empty set.?