Let the distance is x
Distance travel in mud=x6
Distance travel in tar=x2
Distance travel in stream=x3
Ratio of speed in mud,tar,stream=3:5:4
∵time=distancespeedSo
Time taken to cross the mud=x6×13=x18
Time taken to cross the tar=x2×15=x10
Time taken to cross the stream=x12×14=x12
Ratio of time taken to cross mud ,stream,tar=x18:x12:x10
10:15:18