If $+$ means $-$, $-$ means $\times$, $\times$ means $÷$, $÷$ means $+$, what will come in place of the question mark (?) in the given equation?
$$180\times 60-30÷30+20=?$$

Given sign transformations:
* $+\to -$
* $-\to \times$
* $\times \to ÷$
* $÷\to +$

The original expression is:

$$180\times 60-30÷30+20$$

Substituting the signs according to the given conditions, we get:

$$180÷60\times 30+30-20$$

Now, solving the expression using the BODMAS rule:

1. Division ($÷$):

$$180÷60=3$$

The expression becomes: $3\times 30+30-20$
2. Multiplication ($\times$):

$$3\times 30=90$$

The expression becomes: $90+30-20$
3. Addition ($+$):

$$90+30=120$$

The expression becomes: $120-20$
4. Subtraction ($-$):

$$120-20=100$$

Thus, the value of the equation is $100$.