Subject: General Aptitude · Chapter: Time and Distance · Exam: 2016 · Marks: · Difficulty:
With a uniform speed, a car covers a distance in 8 hours. Had the speed been increased by 4 km/ hr, the same distance could have been covered in 7 hours and 30 minutes. What is the distance covered?
(a)420 km
(b)480 km
(c)520 km
(d)640 km
Answer
Answer (as printed): B
Explanation
Let the speed of car be $x$ km/hr Distance = speed × time Distance $=8 x \mathrm{km}$ According to given information $$\begin{aligned} & (x+4) \times 7.5=8 x \\ & \Rightarrow 7.5 x+30=8 x \\ & \Rightarrow 8 x-7.5 x=30 \\ & 30=0.5 x \\ & x=\frac{30}{0.5}=60 \mathrm{km} / \mathrm{hr} \end{aligned}$$