Combined Operations involving Fractions

Without using a calculator, find the value of each of the following.

1. \(\frac{3}{4}-\frac{15}{8}+1\frac{1}{4}-\left( -\frac{1}{2} \right)\)
2. \(2\frac{3}{4}+3\frac{3}{5}\)
3. \(2\frac{2}{3}+\left( -\frac{1}{4} \right)-\frac{1}{12}+\frac{1}{2}\)