Evaluate the statement 20 − (12) ÷ 3 = 6. Solve for the missing number in - 12 / 3 = 6, - (12 / 3) = 6, 18 + + 12 = 98, and 15 + + 12 = 95.

First, perform the division:

$$12 \div 3 = 4$$

Substitute this back into the statement:

$$20 - 4 = 6$$ $$16 = 6$$

This statement is false.

Let the missing number be $x$.

$$x - 12 \div 3 = 6$$

Perform the division first:

$$x - 4 = 6$$

Add 4 to both sides of the equation:

$$x = 6 + 4$$ $$x = 10$$

The missing number is $\boxed{10}$.
The student's work used 30, which is incorrect because $30 - 4 = 26 \neq 6$.

Let the missing number be $y$.

$$y - (12 \div 3) = 6$$

Perform the operation inside the parentheses first:

$$y - 4 = 6$$

Add 4 to both sides of the equation:

$$y = 6 + 4$$ $$y = 10$$

The missing number is $\boxed{10}$.
The student's work used 30, which is incorrect because $30 - 4 = 26 \neq 6$.

Let the missing number be $z$.

$$18 + z + 12 = 98$$

Combine the constant terms on the left side:

$$30 + z = 98$$

Subtract 30 from both sides of the equation:

$$z = 98 - 30$$ $$z = 68$$

The missing number is $\boxed{68}$.
The student's work correctly found 68.

Let the missing number be $w$.

$$15 + w + 12 = 95$$

Combine the constant terms on the left side:

$$27 + w = 95$$

Subtract 27 from both sides of the equation:

$$w = 95 - 27$$ $$w = 68$$

The missing number is $\boxed{68}$.
The student's work correctly found 68.

Let the missing number be $v$.

$$18 + v + 12 = 98$$

Combine the constant terms on the left side:

$$30 + v = 98$$

Subtract 30 from both sides of the equation:

$$v = 98 - 30$$ $$v = 68$$

The missing number is $\boxed{68}$.
The student's work used 65, which is incorrect because $18 + 65 + 12 = 95 \neq 98$.