Answer:
y < 16 - 8x
Step-by-step explanation:
H: hours
45h + 45 = 30h + 75
15h + 45 = 75
15h = 30
h = 2 hours
45 ( 2 ) + 45 = 30 ( 2 ) + 75
90 + 45 = 60 + 75
135 = 135
Therefore the awnser is 2 hours.
If the speed of the stream is x
Time is given by d/r , where r is the rate and d is the distance;
Rate for upstream = (15-x) mph and that of down stream is (15 +x) mph
The time taken will be the same;
Thus; 2/(15-x) = 4/(15+x)
cross multiplying;
30 +2x = 60 -4x
6x = 30
x =5
Therefore the rate of the river is 5 mph
