If $\frac{16}{28} = \frac{x}{21} = \frac{28}{y}$ then the values of x and y are respectively:

Correct Answer: (C) 12 and 49

Given $\frac{16}{28}$ = $\frac{x}{21}$, simplifying the fraction $\frac{16}{28}$ gives $\frac{4}{7}$. Cross-multiplying yields $\frac{4}{7}$ = $\frac{x}{21}$, so x = $\frac{4 \times 21}{7}$ = 12. Similarly, for $\frac{16}{28}$ = $\frac{28}{y}$, cross-multiplying gives 16y = 28 $\times$ 28, resulting in y = $\frac{784}{16}$ = 49.