(3) Let the speed of current = x km/hr And the speed of boat in still water = y km/hr Therefore, rate of downstream = (y + x) km/hr and rate of upstream = (y – x) km/hr According to given question ,
x
y+x
=
1
7
⇒ y=6xand
2.75
y−x
=
11
60
⇒ x = 3 and y = 18 Required distance = Rate of downstream × Time =