In covering a distance of 15 km, A takes 2 hours more than B. If A doubles his speed, then he would take 1 hour less than B. A's speed is:
Select the correct option:
A) 5 km/h  B) 8 km/h  C) 10 km/h  D) 15 km/h  E) 2.5 km/h
Let A's speed be X km/hr.   Then, 15/x - 15/2x = 3   7.5/x = 3   x = 2.5 km/hr.   Answer : 2.5 km/h
<result>E</result>
In covering a distance of 15 km, A takes 2 hours more than B. If A doubles his speed, then he would take 1 hour less than B. A's speed is: