Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
In an arithmetic progression, the first term equals the
n
n
n
th term. What is the sum of the first
n
n
n
terms? a)
2
n
a
2na
2
na
b)
n
2
a
\dfrac{n}{2}a
2
n
a
c)
n
a
na
na
d)
n
(
n
+
1
)
2
a
\dfrac{n(n+1)}{2}a
2
n
(
n
+
1
)
a
Browse the problem library