Question

10 men can cut 15 trees in 2 hours. If 2 men leave the job,how many trees will be cut in 3 hours?

Answer 1

$$\begin{gathered} \mathrm{Using}\mathrm{the}\mathrm{concept}\mathrm{of}\frac{\mathrm{man}*\mathrm{day}}{\mathrm{work}}=\mathrm{constant} \\ \frac{{\mathrm{m}}_1\times {\mathrm{d}}_1}{{\mathrm{w}}_1}=\frac{{\mathrm{m}}_2\times {\mathrm{d}}_2}{{\mathrm{w}}_2} \\ \mathrm{Here}\mathrm{work}\mathrm{is}\mathrm{to}\mathrm{cut}\mathrm{the}\mathrm{tree}. \\ \mathrm{Here}{\mathrm{m}}_1=10,{\mathrm{d}}_1=2\mathrm{hour},{\mathrm{w}}_1=15 \\ \mathrm{and}{\mathrm{m}}_2=10-2=8,{\mathrm{d}}_2=3 \\ \frac{10\times 2}{15}=\frac{8\times 3}{{\mathrm{w}}_2} \\ {\mathrm{w}}_2=\frac{15\times 24}{20}=18\mathrm{tree} \end{gathered}$$