• $\frac{3}{5} = 0.6$

• $\frac{2}{3} \approx 0.666$

• $\frac{7}{9} \approx 0.777$

• $\frac{9}{11} \approx 0.818$

• $\frac{8}{9} \approx 0.888$

Since $0.6 < 0.666 < 0.777 < 0.818 < 0.888$, option (c) is correctly arranged in ascending order.

• $\frac{11}{17} \approx 0.647$

• $\frac{7}{11} \approx 0.636$

• $\frac{5}{9} \approx 0.555$

• $\frac{8}{15} \approx 0.533$

Descending order (largest to smallest): $\frac{11}{17} > \frac{7}{11} > \frac{5}{9} > \frac{8}{15}$ Correct option: (d).

Biggest fraction is $\frac{5}{6}$ and smallest is $\frac{2}{3}$. Difference: $\frac{5}{6} - \frac{2}{3} = \frac{5 - 4}{6} = \frac{1}{6}$ Correct option: (a).

• $\frac{3}{8} = 0.375$

• $\frac{5}{13} \approx 0.384$

• $\frac{2}{5} = 0.400$

• $\frac{4}{9} \approx 0.444$

• $\frac{6}{11} \approx 0.545$

Ascending order: $\frac{3}{8} < \frac{5}{13} < \frac{2}{5} < \frac{4}{9} < \frac{6}{11}$ The 4th fraction is $\frac{4}{9}$. Correct option: (c)

• $\frac{11}{14} \approx 0.7857$

• $\frac{16}{19} \approx 0.8421$

• $\frac{19}{21} \approx 0.9047$

Since $0.7857 < 0.8421 < 0.9047$, option (a) is in ascending order.

• $-\frac{7}{10} = -0.70$

• $\frac{2}{-3} = -\frac{2}{3} \approx -0.666$

• $\frac{5}{-8} = -\frac{5}{8} = -0.625$

For negative numbers, smaller absolute value is larger: $-0.70 < -0.666 < -0.625$ Ascending order: $-\frac{7}{10} < \frac{2}{-3} < \frac{5}{-8}$ Correct option: (d)

Convert boundaries to decimals:

• $\frac{3}{5} = 0.60$

• $\frac{2}{3} \approx 0.667$

Check option (d): $\frac{31}{50} = 0.62$ Since $0.60 < 0.62 < 0.667$, $\frac{31}{50}$ lies between them. Correct option: (d)

Evaluate each expression:

• (a) $(0.09)^2 = 0.0081$

• (b) $0.09$

• (c) $(1 - 0.9)^2 = (0.1)^2 = 0.01$

• (d) $1 - (0.9)^2 = 1 - 0.81 = 0.19$

The value closest to $0$ is $0.0081$. Correct option: (a)

Let the missing digit be $x$. $54.x3 + 543 + 5.43 = 603.26$ $548.43 + 54.x3 = 603.26$ $54.x3 = 603.26 - 548.43 = 54.83$ Comparing digits gives $x = 8$. Correct option: (c)