Question

If $\frac{3}{4}$ is equivalent to $\frac{x}{28}$, then the value of x is

(a) 6
(b) 21
(c) 8
(d) 9

Answer 1

$$\begin{gathered} \frac{3}{4}=\frac{3\times 7}{4\times 7}=\frac{21}{28} \\ \mathrm{It}\mathrm{is}\mathrm{given}\mathrm{that}\frac{3}{4}\mathrm{is}\mathrm{equivalent}\mathrm{to}\frac{x}{28}. \\ \therefore \frac{21}{28}=\frac{x}{28} \\ \Rightarrow x=21 \end{gathered}$$

Hence, the correct option is (b).