Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
Yesterday's price of notebook = $3.45
Today's price of notebook = $3.20
We have to determine the percentage decrease in the cost of notebook.
Percentage decrease = (Decrease 
Old price) 
So, percentage decrease = 
=
= 7.246%
= 7.25%
Therefore, there is 7.25% of decrease in the cost of the notebook.
Answer: 8 weeks
explanation: 125 + 15x = 245
You then have to subtract 125 from both sides so we can isolate our variable which will give us 15x = 120 . Divide 15 from both sides : 15x/15 = 120/15 which will give us x = 8.
Answer:
A committee of 3 members for the education board is to be selected from a pool of 6 prospective candidates – C, D, E, F, G, and H. Candidates C, D and E are male and the rest are females. At least, one of the selected candidates should have a minimum of 10 years cognate experience in the education sector. The committee should have at least one male and a female candidate. Each of the committee members should have studied a different course for a bachelor’s degree.
Which committee would most likely be selected?
Answer: 38.41 minutes
Step-by-step explanation:
The standard error for the difference in means is given by :-
where , 
= Standard deviation for sample 1.
= Size of sample 1.
= Standard deviation for sample 2.
= Size of sample 2.
Let the sample of Latino name is first and non -Latino is second.
As per given , we have
The standard error for the difference in means will be :
Hence, the standard error for the difference in means =38.41 minutes
