Question

A group of 7 people had enough food for a month. A few more people joined them and the food lasted only for 21 days. How many people joined?

Answer 1

Dear student

No.Of days	30	21
No.Of people	7	x

It is indirect variation
$$\begin{gathered} 30\times 7=21\times \mathrm{x} \\ \Rightarrow \mathrm{x}=\frac{30\times 7}{21} \\ \Rightarrow \mathrm{x}=10 \\ \mathrm{So},\mathrm{Number}\mathrm{of}\mathrm{peolpe}\mathrm{joined}=10-7=3 \end{gathered}$$
Regards