Question

Let U = {n, p, q, r, s, t, u, v} A = {n, p, q, r} B = {n, q, s, u}. Find B – A.

Answer 1

i solved as B – A = {n, p, q, r, s, u} which may be incorrect

Answer 2

So, in a more general set builder notation of this, where A, B are sets
\[B-A=\{x:~~x\in B~~~and~~~x\notin A\}\]
in other words, we are looking for elements of B that are not elements of A

Answer 3

If diagrams would help:

Answer 4

thanks for your help