Question

21 please tell me very quickly

a78e8f2189ff20b154e7bc20274e6413.pdf

Answer 1

Let x be the speed of boat and y be the speed of the stream.
4(x + y) + 3(x - y) = 116
                 7x + y = 116 . . . . . (1)
3(x + y) + 4(x - y) = 108
                  7x - y = 108 . . . . . (2)
(1) + (2)
14x = 224
    x = 16
    y = 7(16) - 108
       = 112 - 108
       = 4
Therefore, 
    Speed of boat = 14km/hr
    Speed of stream = 4km/hr