Question Number 189872 by otchereabdullai last updated on 23/Mar/23
$${A}\:{farmer}\:{and}\:{his}\:{son}\:{used}\:\mathrm{20}\:{days}\: \\ $$$${to}\:{weed}\:{a}\:{plot}\:{of}\:{land}\:.\:{If}\:{the}\:{farmer} \\ $$$${uses}\:\mathrm{36}\:{days}\:{to}\:{weed}\:{the}\:{same}\:{plot}\:{of} \\ $$$${land}\:,\:{how}\:{many}\:{days}\:{will}\:{the}\:{son}\: \\ $$$${use}\:{to}\:{weed}\:{the}\:{same}\:{plot}\:{of}\:{land} \\ $$
Answered by Frix last updated on 23/Mar/23
$$\frac{\mathrm{1}}{{f}}+\frac{\mathrm{1}}{{s}}=\frac{\mathrm{1}}{\mathrm{20}} \\ $$$${f}=\mathrm{36} \\ $$$$\frac{\mathrm{1}}{{s}}=\frac{\mathrm{1}}{\mathrm{20}}−\frac{\mathrm{1}}{\mathrm{36}}=\frac{\mathrm{1}}{\mathrm{45}}\:\Rightarrow \\ $$$${s}=\mathrm{45} \\ $$
Commented by otchereabdullai last updated on 23/Mar/23
$${thanks}\:{sir}!\:{am}\:{much}\:{grateful} \\ $$