A boy goes three equal distances, each of length x km, with a speed of y km / hr, 3 y/5 km / hr and 2 y/5 km… · ABC26GN3629

Subject: General Aptitude · Chapter: Time and Distance

A boy goes three equal distances, each of length $x$ km, with a speed of $y \mathrm{km} / \mathrm{hr}, \frac{3 y}{5} \mathrm{km} / \mathrm{hr}$ and $\frac{2 y}{5} \mathrm{km} / \mathrm{hr}$ respectively. If the total time taken is 1 hour, then $x: y$ is equal to
(a)6 : 13
(b)6 : 23
(c)6 : 31
(d)6 : 37
Answer
Answer (as printed): C
Explanation
Total time taken $$\begin{aligned} & =\left[\frac{x}{y}+\frac{x}{\left(\frac{3 y}{5}\right)}+\frac{x}{\left(\frac{2 y}{5}\right)}\right] \text { hours } \\ & =\left(\frac{x}{y}+\frac{5 x}{3 y}+\frac{5 x}{2 y}\right) \text { hours }=\left(\frac{6 x+10 x+15 x}{6 y}\right) \text { hours } \\ & =\left(\frac{31 x}{6 y}\right) \text { hours. } \\ & \therefore \frac{31 x}{6 y}=1 \Leftrightarrow \frac{x}{y}=\frac{6}{31} . \end{aligned}$$

Explanation as extracted from the printed page; notation may be imperfect.

Study loop for Time and Distance

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