Question Number 197373 by sciencestudentW last updated on 15/Sep/23
Answered by Tokugami last updated on 17/Sep/23
$$\mathrm{6}\:\frac{\cancel{\mathrm{km}}}{\cancel{\mathrm{h}}}×\frac{\mathrm{1000}\:\mathrm{m}}{\mathrm{1}\:\cancel{\mathrm{km}}}×\frac{\mathrm{1}\:\cancel{\mathrm{h}}}{\mathrm{60}\:\mathrm{m}}=\mathrm{100}\:\frac{\mathrm{m}}{\mathrm{min}} \\ $$$$\mathrm{8}\:\frac{\cancel{\mathrm{km}}}{\cancel{\mathrm{h}}}×\frac{\mathrm{1000}\:\mathrm{m}}{\mathrm{1}\:\cancel{\mathrm{km}}}×\frac{\mathrm{1}\:\cancel{\mathrm{h}}}{\mathrm{60}\:\mathrm{m}}=\frac{\mathrm{400}}{\mathrm{3}}\:\frac{\mathrm{m}}{\mathrm{min}} \\ $$$$\frac{\mathrm{400}}{\mathrm{3}}{t}=\mathrm{250}+\mathrm{100}{t} \\ $$$$\frac{\mathrm{400}}{\mathrm{3}}{t}−\mathrm{100}{t}=\mathrm{250}+\mathrm{100}{t}−\mathrm{100}{t} \\ $$$$\frac{\mathrm{100}}{\mathrm{3}}{t}×\frac{\mathrm{3}}{\mathrm{100}}=\mathrm{250}×\frac{\mathrm{3}}{\mathrm{100}} \\ $$$${t}=\frac{\mathrm{750}}{\mathrm{100}}=\mathrm{7}.\mathrm{5}\:\mathrm{min} \\ $$$$\left.\mathrm{E}\right)\:\mathrm{None} \\ $$
Commented by sciencestudentW last updated on 19/Sep/23
$${thanks} \\ $$