Question

Tick (✓) the correct answer:
x% of y is y% of?
(a) x
(b) 100x
(c) $\frac{x}{100}$
(d) $\frac{y}{100}$

Answer 1

(a) x

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{required}\mathrm{number}\mathrm{be}z.\mathrm{Then},\mathrm{we}\mathrm{have}: \\ x\%ofy=y\%ofz \\ \Rightarrow \left(y\times \frac{x}{100}\right)=\left(z\times \frac{y}{100}\right) \\ \Rightarrow \frac{yx}{100}=\frac{zy}{100} \\ \Rightarrow z=\left(\frac{yx}{100}\times \frac{100}{y}\right) \\ \Rightarrow z=x \end{gathered}$$