Question Number 47814 by Necxx last updated on 15/Nov/18
$${A}\:{boy}\:{runs}\:{towards}\:{a}\:{man}\:{standing} \\ $$$$\mathrm{150}{m}\:{away}.{Speed}\:{of}\:{boy}\:{is}\:\mathrm{5}{m}/{s} \\ $$$${and}\:{that}\:{of}\:{man}\:{is}\:\mathrm{10}{m}/{s}.{The} \\ $$$${time}\:{and}\:{distance}\:{of}\:{their}\:{meeting} \\ $$$${from}\:{the}\:{boy}^{.} {s}\:{position}\:{are} \\ $$$$\left.{a}\left.\right)\left.\mathrm{15}{s}\:{b}\right)\mathrm{5}{s}\:{and}\:\mathrm{150}{m}\:{c}\right)\mathrm{10}{s}\:{and}\:\mathrm{50}{m} \\ $$$$\left.{d}\right)\mathrm{10}{s}\:{and}\:\mathrm{100}{m} \\ $$
Commented by Necxx last updated on 15/Nov/18
$${please}\:{help} \\ $$
Answered by mr W last updated on 15/Nov/18
$${t}={time}\:{they}\:{run} \\ $$$${boy}\:{runs}\:{distance}\:\mathrm{5}{t} \\ $$$${man}\:{runs}\:{distance}\:\mathrm{10}{t} \\ $$$${they}\:{run}\:{together}\:\mathrm{150}\:{meters}: \\ $$$$\mathrm{5}{t}+\mathrm{10}{t}=\mathrm{150} \\ $$$$\Rightarrow{t}=\mathrm{10}\:{s} \\ $$$${boy}\:{runs}\:\mathrm{5}×\mathrm{10}=\mathrm{50}\:{m} \\ $$$$ \\ $$$$\left.\Rightarrow{answer}\:{c}\right) \\ $$
Commented by Necxx last updated on 15/Nov/18
$${wow}......\:{Thanks}...{its}\:{clear} \\ $$