Answer: 
Step-by-step explanation:
You need to use the following formula:

Where "r" is the radius and
is is the central angle of the arc in radians.
Assuming that that the angle
is the central angle of the arc, and knowing that the radius is 7 centimeters, you can substitute values into the formula.
Therefore, you get:

14/20
14/18
1
7
—————————————////
Answer:
5 bags of cement are required.
Step-by-step explanation:
Since to make concrete, the ratio of cement to sand is 1: 3, if cement and sand are sold in bags of equal mass, to determine how many bags of cement are required to make concrete using 15 bags of sand the following calculation must be done:
Cement = 1
Sand = 3
3 = 15
1 = X
15/3 = X
5 = X
Therefore, 5 bags of cement are required.
No when you subtract the 2 balances, there is a difference of 33.34. 1201.1-38.34=1162.76
The events A and B are not independent.
Given that,
P(A|B) = 0.4
P(A) = 0.5
P(B) = 0.8
Two events A and B are said to be independent, if P(A∩B) = P(A) P(B)
We have, P(A|B) = P(A∩B)/P(B)
Therefore, P(A∩B) = P(A|B) P(B) = 0.4 x 0.8 = 0.32
Now P(A) P(B) = 0.5 x 0.8 = 0.4
So P(A∩B) ≠ P(A)P(B)
Therefore, the events A and B are not independent.
Learn more about independent events at brainly.com/question/22881926
#SPJ4