Question

If x and y vary inversely and x = 15 when y = 6, find y when x = 9.

Answer 1

$x$	15	9
$y$	6	$y_1$

$$\begin{gathered} x\mathrm{and}y\mathrm{var}y\mathrm{inversely}. \\ \mathrm{i}.\mathrm{e}.xy=\mathrm{constant} \\ \mathrm{Now},15\times 6=9\times y_1 \\ \Rightarrow y_1=\frac{15\times 6}{9} \\ \Rightarrow y_1=10 \end{gathered}$$

∴ Value of $y=10$, when x =9