Question

a motorboat cover the distance between the two spots on the river in 8 hours and 12 hours downstream and upstream respectively police. find the time required by the boat to cover this distance in stillwater.

Answer 1

let the speed of bote is x m/s and the speed of stream is y m/s.
from question
x+y=8hour......(1)
x-y=12hour.....(2)
adding (1)&(2)
2x=20hours so value of x is10 hours and it's your answer