If 234579 = 0168 and 124678 = 0359, what is 013479 equal to?

What the pattern is asking you to notice

Each left side is a group of digits taken from $\{0,1,2,3,4,5,6,7,8,9\}$. The right side is made from the digits that are missing.

Check the rule on the given examples

• For $234579$, the missing digits are $0,1,6,8$, so $234579 = 0168$.
• For $124678$, the missing digits are $0,3,5,9$, so $124678 = 0359$.

Apply the same rule to 013479

Digits present in $013479$ are $0,1,3,4,7,9$.

Missing digits from $0$ to $9$ are $2,5,6,8$.

So, $$013479 = 2568$$