Question

If $\frac{2}{5}$ of 50% of x is 10,then x =

(a) 100
(b) 50
(c) 25
(d) 80

Answer 1

$$\begin{gathered} \frac{2}{5}\mathrm{of}50\%\mathrm{of}x=10 \\ \Rightarrow \frac{2}{5}\times \frac{50}{100}\times x=10 \\ \Rightarrow \frac{x}{5}=10 \\ \Rightarrow \frac{x\times 5}{5}=10\times 5 \\ \Rightarrow x=50 \end{gathered}$$

Hence, the correct option is (b).