Answer:
The speed of the boat in still water is 18 mph.
The speed of the current is 2 mph
Step-by-step explanation:
Let x represent the speed of the boat in still water.
Let y represent the speed of the current.
When the boat goes against the current, the speed is 16 mph. Assuming it traveled against the current while going upstream, its total speed would be (x - y) mph. It means that
x - y = 16 (equation 1)
Going downstream, the boat averages 20 mph. Assuming it traveled with the current, its total speed would be (x + y) mph. It means that
x + y = 20 (equation 2)
Adding both equations, it becomes
2x = 36
x = 36/2
x = 18 mph
Substituting x = 18 into equation 1, it becomes
18 - y = 16
y = 18 - 16
y = 2 mph
Answer: 8 pi
Step-by-step explanation: So we know that area of a circle is pi times r^2 so if we reverse that formula it would be square root of 16 pi which would be 4 pi and divide by pi so the radius is 4. And we know that the formula for circumference is 2 times pi times r, so 2 times 4 times pi is 8 pi. 8 pi is the cIrcumference! :)
Answer:
x = 18
Step-by-step explanation:
Given
+ 1 =
+ 7 ( subtract 1 from both sides )
=
+ 6
Multiply through by 15 to clear the fractions
9x = 4x + 90 ( subtract 4x from both sides )
5x = 90 ( divide both sides by 5 )
x = 18
Answer:
2/9
Step-by-step explanation:
16/72 simplify in calculator =2/9