A car takes 15 minutes less to cover a distance of 75 km, if it increases its speed by 10 km/hr from its usual speed. How much time would it take to cover a distance of 300 km using this speed ?
A. 5 hrs
B. $$5\frac{1}{2}$$ hrs
C. 6 hrs
D. $$6\frac{1}{2}$$ hrs
Answer: Option A
Solution(By Examveda Team)
Let the usual speed be x km/hrThen,
$$\eqalign{ & \Leftrightarrow \frac{{75}}{x} - \frac{{75}}{{x + 10}} = \frac{{15}}{{60}} \cr & \Leftrightarrow x\left( {x + 10} \right) = 3000 \cr & \Leftrightarrow {x^2} + 10x - 3000 = 0 \cr & \Leftrightarrow \left( {x + 60} \right)\left( {x - 50} \right) = 0 \cr & \Leftrightarrow x = 50 \cr} $$
∴ Required time :
$$\eqalign{ & = \left( {\frac{{300}}{{60}}} \right){\text{hrs}} \cr & = 5{\text{ hrs}} \cr} $$
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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