Convert the mixed number to an improper fraction:

\( 1\dfrac{1}{4} = \dfrac{5}{4} = 1.25 \).

\\( \\dfrac{11}{8} = 1.375 \\).

So \( \dfrac{11}{8} > 1\dfrac{1}{4} \).

The true statement is option 2.

Convert each fraction to twelfths:

• \( \dfrac{1}{2} = \dfrac{6}{12} \)
• \( \dfrac{2}{3} = \dfrac{8}{12} \)
• \( \dfrac{3}{4} = \dfrac{9}{12} \)
• \( \dfrac{5}{6} = \dfrac{10}{12} \)

From smallest to largest: \( \dfrac{6}{12} < \dfrac{8}{12} < \dfrac{9}{12} < \dfrac{10}{12} \).

So the correct order is 1/2,2/3,3/4,5/6.

Convert to improper fractions:

\( 2\dfrac{2}{5} = \dfrac{2 \times 5 + 2}{5} = \dfrac{12}{5} \)

\( 1\dfrac{3}{10} = \dfrac{1 \times 10 + 3}{10} = \dfrac{13}{10} \)

Add them:

\( \dfrac{12}{5} + \dfrac{13}{10} = \dfrac{24}{10} + \dfrac{13}{10} = \dfrac{37}{10} \).

Answer: \( \dfrac{37}{10} \).

Use a common denominator of 12:

\( \dfrac{3}{4} = \dfrac{9}{12},\quad \dfrac{5}{6} = \dfrac{10}{12} \).

So \( \dfrac{3}{4} + \dfrac{5}{6} = \dfrac{9}{12} + \dfrac{10}{12} = \dfrac{19}{12} \).

Answer: \( \dfrac{19}{12} \).

Multiply numerators and denominators:

\( \dfrac{5}{6} \times \dfrac{4}{9} = \dfrac{5 \times 4}{6 \times 9} = \dfrac{20}{54} \).

Simplify \( \dfrac{20}{54} \) by dividing top and bottom by 2:

\( \dfrac{20}{54} = \dfrac{10}{27} \).

Answer: \( \dfrac{10}{27} \).

Change division to multiplication by the reciprocal:

\( \dfrac{7}{9} \div \dfrac{2}{3} = \dfrac{7}{9} \times \dfrac{3}{2} = \dfrac{21}{18} \).

Simplify \( \dfrac{21}{18} \) by dividing by 3:

\( \dfrac{21}{18} = \dfrac{7}{6} \).

Answer: \( \dfrac{7}{6} \).

Convert the mixed number to an improper fraction:

\( 1\dfrac{3}{4} = \dfrac{7}{4} \).

Now divide by \( \dfrac{2}{3} \):

\( \dfrac{7}{4} \div \dfrac{2}{3} = \dfrac{7}{4} \times \dfrac{3}{2} = \dfrac{21}{8} \).

As a mixed number, \( \dfrac{21}{8} = 2\dfrac{5}{8} \).

So the correct option is 2.

Convert \( 2\dfrac{2}{3} \) to an improper fraction:

\( 2\dfrac{2}{3} = \dfrac{8}{3} \).

Now divide by \( \dfrac{3}{4} \):

\( \dfrac{8}{3} \div \dfrac{3}{4} = \dfrac{8}{3} \times \dfrac{4}{3} = \dfrac{32}{9} \).

As a mixed number, \( \dfrac{32}{9} = 3\dfrac{5}{9} \).

So the correct option is 3.

\( \dfrac{3}{8} \times 400 = \dfrac{3 \times 400}{8} \).

Compute \( 400 \div 8 = 50 \), so:

\( \dfrac{3 \times 400}{8} = 3 \times 50 = 150 \).

Answer: 150.

First do the multiplication:

\( \dfrac{5}{8} \times \dfrac{7}{12} = \dfrac{35}{96} \).

Now add \( \dfrac{2}{3} \). Write \( \dfrac{2}{3} \) with denominator 96:

\( \dfrac{2}{3} = \dfrac{64}{96} \).

So \( \dfrac{2}{3} + \dfrac{35}{96} = \dfrac{64}{96} + \dfrac{35}{96} = \dfrac{99}{96} \).

Simplify by dividing top and bottom by 3:

\( \dfrac{99}{96} = \dfrac{33}{32} \).

Answer: \( \dfrac{33}{32} \).