The area of a circle is equal to the radius squared times pie, basically:

The radius is 3, so we multiply 3 times 3 times pie to get the area.
You're gonna want to plug in the following into a calculator:

After getting 28.26 from such calculator, you need to round to the tenths place. In this number, the tenths place is the 2 next to the decimal on the right. Because the number after the 2 is a 6, that means we need to simplify the answer to (28.3). When you are rounding a number, you look at the number to the right, if it is 5 or bigger, add one and remove the rest, if it is less than 5, just get rid of the rest and leave it as it is.

To solve, we have to look for a pattern.

When you see pyramids like these, they usually tell you to add/multiply the two numbers to get a third number that goes on top. Here, we can see 3 and 4 on the bottom left hand corner. The third number on top of both 3 and 4 is 7. 3 + 4 = 7. Let's check 4 and 5, the middle two numbers. 4 + 5 = 9, and that number is on top of 4 and 5. Therefore, we can confirm that this is an addition pyramid.

Since 7 + 9 is 16 and 9 + 8 is 17, all we need to do in order to get the final number is to add 16 to 17.


Step-by-step explanation:
The easiest approach is to realise that one hour is 3 times longer than
20
minutes. The longer the time, the more they will pave.
2
15
of a mile, in 20 minutes, how much in 60 minutes?#
They will pave 3 times more.
2
15
×
3
1
=
6
15
of a mile
6
15
=
2
5
of a mile
You could also use the 'unitary method' where you find out how much they pave in ONE minute (divide by
20
) and them multiply by
60
to find how much in one hour.
Look at what happens:
2
15
÷
20
×
60
=
2
15
×
1
20
×
60
3
=
2
15
×
3
←
exactly the same maths.
=
2
5
Answer:
The farmer should plant 14 additional trees, for maximum yield.
Step-by-step explanation:
Given



So, we have:


Required
The additional trees to be planted for maximum yield
The function is:


Open bracket



Rewrite as:

Differentiate

Equate
to 0 and solve for x to get the maximum of x


Divide by -4

The farmer should plant 14 additional trees, for maximum yield.