Difference of speed of boat in downstream and upstream is 7km hr and the time taken by the boat to t...........

Quantitative Aptitude(IBPS CL) Time & distance

Difference of speed of boat in downstream and upstream is 7km/hr and the time taken by the boat to travel 45 km in downstream is 80 minutes more than the time taken to travel 13 km in upstream. Due to cyclone, speed of current becomes twice and thus it can cover D km in upstream in time which is equal to new speed of current. Find D? (Note: speed of boat in still water is multiple of 5)

छोटे Courses बड़े Results

Master Time & distance

Prepare through Micro-courses

Try Now

Explanation:

Let the speed of boat in still water be x km/hr and that of speed of current be y km/hr
ATQ
x+y−(x−y)=7
y=3.5 km/hr

x =10 & 14 (14 is neglected because x should be multiple of 5)
∴ x=10 km/h
New speed of current = 7 km/hr
Distance travelled in upstream =7×(10−7)
= 21 km