Answer:
The speed is still water is
.
Step-by-step explanation:
Dimentionally speaking, speed is distance divided by time. Since, the person is travelling downstream, absolute speed is equal to the sum of current speed and speed of the person regarding current. Both components are constant. That is:

Where:
- Current speed, measured in miles per hour.
- Speed of the person regarding current, measured in miles per hour.
- Distance travelled downstream, measured in miles.
- Time spent on travelling, measured in hours.
Speed in still water occurs when current speed is zero. Then, such variable is obtained after subtracting current speed on both sides of the expression. Hence:

The speed is still water is
.
Answer:
A
Step-by-step explanation:
To find the area of a building.
and to make a small farm
Answer:
C = $2.40
n = 6
Step-by-step explanation:
For Noelle,
Equation that represents the monthly cost 'C',
C = 0.2n + 1.20
Here, n = number of checks written in a month
For Micah,
Monthly cost for writing checks 'C' = $1.20
Number of checks 'n' = 3
Since, Cost of writing checks ∝ Number of checks written
C' ∝ n
C' = kn
k = 
Here, k = proportionality constant
For C' = 1.2 and n = 3
k = 
k = 0.4
Equation will be,
C' = 0.4n
For any month C = C'
Therefore, 0.2n + 1.20 = 0.4n
0.4n - 0.2n = 1.20
0.2n = 1.20
n = 6
Number of checks written by Noelle and Micah = 6
For n = 6,
C = 0.2(6) + 1.20
C = $2.40
Cost of writing checks = $2.40
1200cm
20x50= 1000x1/2x2= 1000
10x20=200x2x1/2=200
1000+200=1200
the area of the kite is 1200 cm