IBM Aptitude Questions: A man pushes downstream 30 km and upstream 18 km, taking 5 hours each time. What is the speed of the stream (current)?

1. A man pushes downstream 30 km and upstream 18 km, taking 5 hours each time. What is the speed of the stream (current)?

Options:

1. 1.2 KM/HR
2. 1.7 KM/HR
3. 2.8 KM/HR
4. 4.8 KM/HR

Answer

A 1.2 KM/HR

Explanation:

Consider:

x=speed of boat

y=speed of current

=30/ (x+y)=18/(x-y)=5 

By solving y=1.2 km/hr