Question 598787
Let speed of boat in still water = X mph
& speed of the stream = Y mph

So effective speed of the boat while going downstream = (X + Y) mph
& effective speed of the boat while going upstream = (X - Y) mph

using the formula (Time*Speed = Distance), we get
12*(X + Y) = 288 (for downstream journey)
X + Y = 288/12
X + Y = 24  (equation 1)


Using the same formula, we get
36*(X - Y) = 288 (for upstream journey)
X - Y = 288/36
X - Y = 8 (equation 2)

On Adding equation 1 & 2, we get
2X = 32
i.e. X = 16

using the value of X = 16 in equation 1, we get
16 + Y = 24
i.e. Y = 8

So speed of boat in still water = 16 mph
& speed of the stream = 8 mph