\( \begin{array}{lll}\text { (16) } \frac{1}{2}+1 \frac{1}{5} & \text { (17) }-1 \frac{3}{4}+-2 \frac{1}{2} & \text { (18) } 3+1 \frac{1}{3} \\ \text { (19) }-2 \frac{2}{5}+1 \frac{9}{10} & \text { (20) } 12+\frac{1}{3} & \text { (21) } 1 \frac{5}{7}+\frac{3}{14} \\ \text { (22) } \frac{2 \frac{1}{4}}{1} \frac{1}{2} & \text { (23) } 1+\frac{1}{2} \times \frac{1}{3} & \text { (24) } 1+\frac{1}{2}+\frac{1}{3} \\ \text { (25) } 1+\left(\frac{1}{2}+\frac{1}{3}\right) & \text { (26) } 2 \frac{1}{2}+1 \frac{1}{2} \times-\frac{2}{5} & \text { (27) } \frac{3 \frac{2}{3} \times \frac{5}{11}}{2}\end{array} \)

**(16)** Convert the mixed number: \[ 1\frac{1}{5} = \frac{6}{5} \] Then add: \[ \frac{1}{2} + \frac{6}{5} = \frac{5}{10} + \frac{12}{10} = \frac{17}{10} = 1\frac{7}{10} \] **(17)** Convert each mixed number: \[ -1\frac{3}{4} = -\frac{7}{4}, \quad -2\frac{1}{2} = -\frac{5}{2} = -\frac{10}{4} \] Now add: \[ -\frac{7}{4} + \left(-\frac{10}{4}\right) = -\frac{17}{4} = -4\frac{1}{4} \] **(18)** Convert the mixed number: \[ 1\frac{1}{3} = \frac{4}{3} \] Then add to 3: \[ 3 + \frac{4}{3} = \frac{9}{3} + \frac{4}{3} = \frac{13}{3} = 4\frac{1}{3} \] **(19)** Convert each mixed number: \[ -2\frac{2}{5} = -\frac{12}{5}, \quad 1\frac{9}{10} = \frac{19}{10} \] Bring \(-\frac{12}{5}\) to denominator 10: \[ -\frac{12}{5} = -\frac{24}{10} \] Then add: \[ -\frac{24}{10} + \frac{19}{10} = -\frac{5}{10} = -\frac{1}{2} \] **(20)** Express 12 as a fraction with denominator 3: \[ 12 = \frac{36}{3} \] Then add: \[ \frac{36}{3} + \frac{1}{3} = \frac{37}{3} = 12\frac{1}{3} \] **(21)** Convert the mixed number: \[ 1\frac{5}{7} = \frac{12}{7} \] Now add: \[ \frac{12}{7} + \frac{3}{14} = \frac{24}{14} + \frac{3}{14} = \frac{27}{14} = 1\frac{13}{14} \] **(22)** Rewrite the mixed numbers as improper fractions: \[ 2\frac{1}{4} = \frac{9}{4}, \quad 1\frac{1}{2} = \frac{3}{2} \] Divide: \[ \frac{\frac{9}{4}}{\frac{3}{2}} = \frac{9}{4} \times \frac{2}{3} = \frac{18}{12} = \frac{3}{2} = 1\frac{1}{2} \] **(23)** First perform the multiplication: \[ \frac{1}{2} \times \frac{1}{3} = \frac{1}{6} \] Then add 1: \[ 1 + \frac{1}{6} = \frac{6}{6} + \frac{1}{6} = \frac{7}{6} = 1\frac{1}{6} \] **(24)** Add the numbers by finding a common denominator: \[ 1 = \frac{6}{6},\quad \frac{1}{2} = \frac{3}{6},\quad \frac{1}{3} = \frac{2}{6} \] Then: \[ \frac{6}{6} + \frac{3}{6} + \frac{2}{6} = \frac{11}{6} = 1\frac{5}{6} \] **(25)** Perform the operation inside the parentheses first: \[ \frac{1}{2} + \frac{1}{3} = \frac{3}{6} + \frac{2}{6} = \frac{5}{6} \] Then add 1: \[ 1 + \frac{5}{6} = \frac{6}{6} + \frac{5}{6} = \frac{11}{6} = 1\frac{5}{6} \] **(26)** Convert the mixed numbers: \[ 2\frac{1}{2} = \frac{5}{2}, \quad 1\frac{1}{2} = \frac{3}{2} \] First perform the multiplication: \[ \frac{3}{2} \times \left(-\frac{2}{5}\right) = -\frac{6}{10} = -\frac{3}{5} \] Then add: \[ \frac{5}{2} + \left(-\frac{3}{5}\right) \] Bring to a common denominator (10): \[ \frac{5}{2} = \frac{25}{10}, \quad -\frac{3}{5} = -\frac{6}{10} \] So: \[ \frac{25}{10} - \frac{6}{10} = \frac{19}{10} = 1\frac{9}{10} \] **(27)** Convert the mixed number to an improper fraction: \[ 3\frac{2}{3} = \frac{11}{3} \] Multiply: \[ \frac{11}{3} \times \frac{5}{11} = \frac{55}{33} = \frac{5}{3} \] Now divide by 2: \[ \frac{\frac{5}{3}}{2} = \frac{5}{3} \times \frac{1}{2} = \frac{5}{6} \]