We have been given that the upstream speed is
and the down stream speed is
.
Let the fisherman traveled a distance of x miles.
The total time of the trip is 6 hours.
Relations between speed (s), time (t) and distance (d) is 
Hence, 
Time upstream + time downstream = 6

lcm = 10

=> 
Cross multiplying, 
x = 20 miles .. Answer.
baki baki ni ore nani wo kokoro wo da yo kunagona no kudake nani wo?
40(60/100) 4(6/10) =24/10 = 2.4
Answer: Length of shorter side is 2.8 cm.
Explanation:
Since we have given that
Dimensions of a room are given by

On a plan, the longer side = 4 cm
As we know that the ratio of original room is equal to ratio of plan room
So,

So, length of shorter side is 2.8 cm.