Question Number 66868 by John Kaloki Musau last updated on 20/Aug/19
$${A}\:{town}\:{N}\:{is}\:\mathrm{340}{km}\:{due}\:{west}\:{of}\: \\ $$$${town}\:{G}\:{and}\:{town}\:{K}\:{is}\:{due}\:{west}\: \\ $$$${of}\:{town}\:{N}.\:{A}\:{helicopter}\:{Zebra}\: \\ $$$${left}\:{G}\:{for}\:{K}\:{at}\:\mathrm{9}{a}.{m}.\:{Another}\: \\ $$$${helicopter}\:{Buffalo}\:{left}\:{N}\:{for}\:{K} \\ $$$${at}\:\mathrm{11}{a}.{m}.\:{Helicopter}\:{Buffalo} \\ $$$${travelled}\:{at}\:{an}\:{average}\:{speed}\:{of}\: \\ $$$$\mathrm{20}{km}/{h}\:{faster}\:{than}\:{helicopter} \\ $$$${Zebra}.\:{If}\:{both}\:{helicopters}\:{reached} \\ $$$${K}\:{at}\:\mathrm{12}.\mathrm{30}{p}.{m},\:{find}\:{the}\:{speed}\:{of}\: \\ $$$${helicopter}\:{Buffalo}. \\ $$
Commented by John Kaloki Musau last updated on 20/Aug/19
$$\boldsymbol{{The}}\:\boldsymbol{{answer}}\:\boldsymbol{{is}}\:\mathrm{205}\boldsymbol{{km}}/\boldsymbol{{h}}. \\ $$$$\boldsymbol{{please}}\:\boldsymbol{{do}}\:\boldsymbol{{it}}. \\ $$
Commented by Prithwish sen last updated on 20/Aug/19
$$\mathrm{let}\:\mathrm{the}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{zebra}\:\mathrm{is}\:\boldsymbol{\mathrm{u}}\:\mathrm{km}\diagup\mathrm{hr} \\ $$$$\therefore\:\mathrm{the}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{buffalo}\:=\:\left(\boldsymbol{\mathrm{u}}+\mathrm{20}\right)\:\mathrm{km}\diagup\mathrm{hr} \\ $$$$\mathrm{the}\:\mathrm{distance}\:\mathrm{between}\:\mathrm{K}\:\mathrm{and}\:\mathrm{N}\:\mathrm{is}\:\boldsymbol{\mathrm{S}}\:\mathrm{km} \\ $$$$\mathrm{S}+\mathrm{340}=\frac{\mathrm{7u}}{\mathrm{2}}\:…….\left(\mathrm{i}\right) \\ $$$$\mathrm{S}\:=\:\frac{\mathrm{3}\left(\mathrm{u}+\mathrm{20}\right)}{\mathrm{2}}\:…….\left(\mathrm{ii}\right) \\ $$$$\mathrm{solving}\:\:\boldsymbol{\mathrm{u}}\:=\:\mathrm{185}\:\mathrm{km}\diagup\mathrm{hr} \\ $$$$\therefore\:\mathrm{the}\:\mathrm{speed}\:\mathrm{of}\:\mathrm{buffalo}\:=\:\left(\mathrm{185}+\mathrm{20}\right)\mathrm{km}\diagup\mathrm{hr} \\ $$$$=\mathrm{205km}\diagup\mathrm{hr} \\ $$
Commented by John Kaloki Musau last updated on 20/Aug/19
$${I}\:{am}\:{very}\:{grateful} \\ $$