question_answer

If x varies inversely as y when\[x=40\], and\[y=600\], then find y, when \[x=400.\]

Answer:

Here, x varies inversely as y

Hence, \[{{x}_{1}}{{y}_{1}}={{x}_{2}}{{y}_{2}}\]

\[\because \,\,{{x}_{1}}=\text{ }40,{{y}_{1}}=\text{ }600,{{x}_{2}}=\text{ }400,{{y}_{2}}=\text{ }?\]

\[40\times 600=400\times {{y}_{2}}\]

\[\Rightarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{{y}_{2}}=\frac{40\times 600}{400}=60\]