A boat takes 90 minutes less to travel 36 km downstream than to travel the same distance in upstream
Answers
Answered by
1
Your question is incomplete...but I think that it is this question:
A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
Let the speed of the stream x mph. Then,
Speed downstream = (10 + x) mph,
Speed upstream = (10 - x) mph.
36 - 36 = 90
(10 - x) (10 + x) 60
72x x 60 = 90 (100 - x2)
x2 + 48x - 100 = 0
(x+ 50)(x - 2) = 0
x = 2 mph.
Answered by
4
Answer:
Very easy by this X=1/2(down stream+up stream)
X=1/2[(X+Y) +(X-Y) ]
GIVEN X=10MPH
NOW PUT X=10 IN EQUATION
LHS=10
NOW PUT X =10 is Also in RHS
WHEN YOU PUT Y=2mph(from option) IN RHS THEN 10 =10 (LHS =RHS)
now ans is 2 mph
Similar questions