Question

If $\frac{4}{7}$ of 49% of x is 21,then x =

(a) 125
(b) 98
(c) 84
(d) 75

Answer 1

$$\begin{gathered} \frac{4}{7}\mathrm{of}49\%\mathrm{of}x=21 \\ \Rightarrow \frac{4}{7}\times \frac{49}{100}\times x=21 \\ \Rightarrow \frac{7x}{25}=21 \\ \Rightarrow \frac{7x\times 25}{25}=21\times 25 \\ \Rightarrow x=\frac{21\times 25}{7} \\ \Rightarrow x=75 \end{gathered}$$

Hence, the correct option is (d).