Question

if X varies inversely as y and y= 15 when x=8 , then find y when x=8​

Answer 1

Answer:

Table:-

$\boxed{\begin{array}{c|c|c}x & 8 & 12 \\ y & 15 & ?\end {array}}$

${:}\longrightarrow$$\sf x\propto {\dfrac {1}{y}}$

• Product of extremes = Product of means

${:}\longrightarrow$$\sf x_1y_2=x_2y_1$

${:}\longrightarrow$$\sf 8\times y_2=12\times15$

${:}\longrightarrow$$\sf 8 y_2 =180$

${:}\longrightarrow$$\sf y_2=\cancel{\dfrac {180}{8}}$

${:}\longrightarrow$$\bf y_2=22.5$