Question

A person drives his car for $3$ hours at a speed of $40$ km/hr and for $4.5$ hours at a speed of $60$ km/hr. At the end of it, he finds that he was covered $\frac{3}{5}$ of the total distance. What is the uniform speed with which he should further drive to cover the remaining distance in $4$ hours?

• A. $35$ km/hr
• B. $20$ km/hr
  
• C. $65$ km/hr
  
• D. $50$ km/hr
  

Answer 1

Answer: (C)

$65$ km/hr

Let the total distance of the journey be D km.

Then,
Distance covered by the person = $(3\times 40+4.5\times 60)km=120km+270km=390km.$
Given, $\frac{3}{5}\times D=390\Rightarrow D=390\times \frac{5}{3}=650km$
Remaining distance $=650km-390km=260km$
$\therefore Requireduniformspeed=\frac{260}{4}=65km/hr.$