<PRE><B>Question 330751</B>
Let speed of boat in still water be x km/hr. and speed of stream be y km/hr.

Therefore,

Upstream, effective speed of boat = x - y = 352/4 = 88. This means, x = y + 88

Downstream, effective speed of boat = x + y = 352/2 = 176

Substituting value of x, 

y + 88 + y = 176
2y = 176 - 88 = 88
Speed of stream, y = 44 km/hr
Speed of boat in still water, x = 44 + 88 = 132 km/hr</PRE>