Question

19. A boat goes 20km upstream and 28 km downstream in 6 hrs. it goes 30 km upstream and 21 km downstream in 6.5 hrs. find the speed of boat in still water and speed of stream.

Answer 1

Answer:

If speed of the boat be x and stream speed be y 

from the given question, 

24/(x-y) + 28/(x+y) = 6 

30/(x-y) + 21/(x+y) = 6.5 

Taking 1/(x-y) as X and 1/(x+y) as Y 

24X + 28Y = 6 

30X + 21Y = 6.5 

solving for X and Y==> 

X = 1/6 and Y = 1/14 

so x-y = 6 and x+y = 14 

hence 

x = 10 kmph and y = 4kmph

Step-by-step explanation:

hope it right