Question

A and B are two cars travelling to a destination which is 360 kilometres away. A takes 4 hours to reach the destination. How much time will it take B to reach the destination if the speeds of A and B are in the ratio 9: 12?

Answer 1

Answer:

$Time \:to \:reach\: the \: destination \:by \:B=3\:hours$

Step-by-step explanation:

Distance of the destination (d) = 360 km,

Time taken to reach the destination by A (t)= 4 hr

$Speed \: of \: A = \frac{d}{t}\\= \frac{360}{4}\\= 90 \: km/hr\: ---(1)$

$Let \: speed \: of \: B = x\: km/hr$

$Ratio \: of \: speeds \: of \: A \:and \:B = 9:12$

$\implies \frac{90}{x} = \frac{9}{12}$

$\implies \frac{90\times 12}{9} = x$

$\implies 120 = x$

Therefore.,

$Speed \: of \: B = 120\:km/hr$

$Time \:to \:reach\: the \: destination \:by \:B \\= \frac{d}{x}\\= \frac{360}{120} = 3 \:hours$

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