SOLUTION: Sonal and Deepali started swimming towards each other simultaneously from points A and B respectively situated at two ends of a 96 km long stretch of a river. Destinations of Deepa

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Question 1114085: Sonal and Deepali started swimming towards each other simultaneously from points A and B respectively situated at two ends of a 96 km long stretch of a river. Destinations of Deepali and Sonal were points A and B respectively. Both of them could swim at 12 kmph in still water. When they started, it was high tide and Sonal swam against the stream. As soon as they met, the tide changed to low tide and then Deepali faced the resistance of the stream. Deepali and Sonal took 7 hr 12 min and 8 hr 34 min to reach their destinations respectively.
1)Find the speed of the stream during low tide?
2)If they had continued to swim back to their respective starting points after reaching their destinations, then where would they have met during the return journey?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Sonal and Deepali started swimming towards each other simultaneously from points A and B respectively situated at two ends of a 96 km long stretch of a river.
Destinations of Deepali and Sonal were points A and B respectively.
Both of them could swim at 12 kmph in still water.
When they started, it was high tide and Sonal swam against the stream.
As soon as they met, the tide changed to low tide and then Deepali faced the resistance of the stream.
Deepali and Sonal took 7 hr 12 min and 8 hr 34 min to reach their destinations respectively.
:
1)Find the speed of the stream during low tide?
A to B = 96 km
A-------------d*-----------------------B
let d = dist from A to the meeting point
let c = the rate of the current (assume it is same in both directions)
then
(12-c) = speed against the current
(12+c) = the speed with
Write a time equation; time = dist/speed
D traveled d dist while S traveled (96-d)
d%2F%28%2812%2Bc%29%29 = %28%2896-d%29%29%2F%28%2812-c%29%29
cross multiply
d(12-c) = (12+c)(96-d)
12d - dc = 1152 - 96c - 12d - dc
Add dc to both sides
12d = 1152 - 96c - 12d
12d + 12d = 1152 - 96c
24d = 1152 - 96c
Simplify, divide by 24
d = 48 - 4c
:
Write an time equation for Deep going A to B
%28%2896-d%29%29%2F%2812-c%29 + d%2F%2812%2Bc%29 + %28%2896-d%29%29%2F%2812-c%29 = 7.2 hrs



2)If they had continued to swim back to their respective starting points after reaching their destinations, then where would they have met during the return journey?