A car X takes 3 hours more than a bus Y in covering 40 km. If the car triples its speed it takes 1 hour less than bus. What is the speed of the car?
Choose the correct answer: A) 6 km/hr B) 6.25 km/hr C) 6.67 km/hr D) 7 km/hr E) None of these
Explanation :   Let the car's speed be x km/hr.   =&gt; 40/x-40/(3x)=4   =&gt; 80/3x=4   =&gt; 12x=80   =&gt; x=6.67 km/hr   Answer : 6.67 km/hr
<result>C</result>
A car X takes 3 hours more than a bus Y in covering 40 km. If the car triples its speed it takes 1 hour less than bus. What is the speed of the car?