What is the value of $$\frac{144}{33} \times \frac{11}{12} - \frac{132}{13} \times \frac{52}{12}$$ ?​

What should come in place of the question mark (?) in the following question?
​$$27\frac{1}{2} + 15\frac{3}{4} - 12\frac{2}{5} + 18\frac{4}{5} = ?$$​​

Simplify the following.
​$$7\frac{1}{2} \div \left\{ 4\frac{1}{4} - \frac{1}{2} \times \left( 2\frac{1}{2} - 1\frac{1}{4} - \frac{3}{4} \right) \right\}$$​​

What value will come in place of question mark (?) in the following question?
​$$\left(9^2 \times 23 + 7^3 \times 8 + ?\right){\frac{1}{2}} = 87$$​​