Answer:
This sum is the sum of an arithmetic sequence. There is a formula for the sum of an arithmetic sequence which can be looked up or derived by a variety of means.
A nice approach for this sequence is the following. Notice that the sum of first and last number in the sequence is the same as the sum of the second and second last, and also the same as the sum of the third and third last, and so on.
There are n of these pairs. So the desired sum is n x (first number + last number). But the first number is 1 and the last on is 2n. Thus the desired sum is n(1 + 2n).
Hope this helps!!
Mark Brainleast!!!!!!!!!!!
The new pool is 18.84 feet larger in circumference than the old one.
<u>Explanation:</u>
Given:
Circumference of the pool = 47.1 feet
Diameter of the new pool, d = 21 feet
radius, r = 21/2 feet
Circumference of the new pool = ?
We know:
Circumference = 2πr
where,
r is the radius
On substituting the value:
C = 
C = 65.94 feet
The difference in circumference of the two pools = 65.94 - 47.1 feet
= 18.84 feet
Therefore, the new pool is 18.84 feet larger in circumference than the old one.
Answer: 4
Step-by-step explanation:
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