The speed of the current in a river is 6 miles per hour
<em><u>Solution:</u></em>
Given that,
Speed of boat in still water = 20 miles per hour
Time taken = 3 hours
Distance downstream = 78 miles
To find: Speed of current
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then: </u></em>
Speed downstream = (u + v) km/hr
Speed upstream = (u - v) km/hr
<em><u>Therefore, speed downstream is given as:</u></em>
We know that,
Speed downstream = (u + v)
26 = 20 + v
v = 26 - 20
v = 6 miles per hour
Thus speed of the current in a river is 6 miles per hour
I believe the answer is 9.7e-6
Answer:
90
Step-by-step explanation:
10+67
7586+65
576845=8757685
2+88=90
Answer:
(a) 
(b) Domain: 
<em>(See attachment for graph)</em>
(c) 
Step-by-step explanation:
Given
Solving (a): A function; l in terms of w
All we need to do is make l the subject in
Divide through by 2
Subtract w from both sides
Reorder
Solving (b): The graph
In (a), we have:
Since l and w are the dimensions of the fence, they can't be less than 1
So, the domain of the function can be
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To check this
When 
When 
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<em>See attachment for graph</em>
<em></em>
Solving (c): Write l as a function 
In (a), we have:
Writing l as a function, we have:
Substitute for l in
becomes
