Use the diagram to explain how to find the sum of a. the first 100 natural numbers.
b. Use this technique to find 1+2+3+4+...+201.
1
+
2
+
3
+
4
+
...
+
97
+
98
+
99
+
100
101
101
101
101

The expression 1 plus 2 plus 3 plus 4 plus ellipsis plus 97 plus 98 plus 99 plus 100 has arcs connecting 1 and 100, 2 and 99, 3 and 98, and 4 and 97. Below each arc is the number 101.
a. Choose the correct answer below.
A.
There are 50 sums of 101 as shown by the arcs. So the sum of the first 100 natural numbers is 50•101=5050.
This is the correct answer. B.
There are 100 sums of 101 as shown by the arcs. So the sum of the first 100 natural numbers is 100•101=​10,100.
C.
There are 50 sums of 101 as shown by the arcs. So the sum of the first 100 natural numbers is 50+101=151.
Your answer is not correct. D.
There are 100 sums of 101 as shown by the arcs. So the sum of the first 100 natural numbers is 100+101=201.
b. The sum of 1+2+3+4+...+201 is nothing.