Question 742105
speed of stream =x

speed of boat in still water =8

time down stream = 60/(8+x)

time down stream = 60/(8-x)

time up + time down = 16 hours

{{{60/(8-x) +60/(8+x) = 16}}}


Multiply equation by (8-x)(8+x)


{{{60(8+x)+60(8-x)=16(64-x^2)}}}

{{{480+60x+480-60xx=1024-16x^2}}}


{{{16x^2=1024-960}}}


{{{16x^2=64}}}

x^2=4

x= +/- 2

ignore negative

x=2