A takes 2 hours more than B to walk d km, but if A doubles his speed, then he can make it in 1 hour less than B. How much times does B required for walking d km ?
A. $$\frac{d}{2}$$ hours
B. 3 hours
C. 4 hours
D. $$\frac{2d}{3}$$ hours
Answer: Option C
Solution(By Examveda Team)
Suppose B takes x hours to walk d kmThen, A takes (x + 2) hours to walk d km
A's speed = $$\left( {\frac{d}{{x + 2}}} \right)$$ km/hr and
B's speed = $$\left( {\frac{d}{{x}}} \right)$$ km/hr
A's new speed = $$\left( {\frac{2d}{{x + 2}}} \right)$$ km/hr
$$\eqalign{ & \therefore \frac{d}{{\left( {\frac{d}{x}} \right)}} - \frac{d}{{\left( {\frac{{2d}}{{x + 2}}} \right)}} = 1 \cr & \Leftrightarrow x - \left( {\frac{{x + 2}}{2}} \right) = 1 \cr & \Leftrightarrow x - 2 = 2 \cr & \Leftrightarrow x = 4 \text{ hours} \cr} $$
Related Questions on Speed Time and Distance
A. 48 min.
B. 60 min.
C. 42 min.
D. 62 min.
E. 66 min.
A. 262.4 km
B. 260 km
C. 283.33 km
D. 275 km
E. None of these
A. 4 hours
B. 4 hours 30 min.
C. 4 hours 45 min.
D. 5 hours
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