Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
The infinite geometric series
∑
n
=
1
∞
3
4
n
\displaystyle\sum_{n=1}^{\infty}\dfrac{3}{4^{n}}
n
=
1
∑
∞
4
n
3
has sum
S
=
1
S=1
S
=
1
. What is the least positive integer
N
N
N
for which
∣
S
−
S
N
∣
<
0.001
|S-S_N|<0.001
∣
S
−
S
N
∣
<
0.001
? a)
6
6
6
b)
8
8
8
c)
5
5
5
d)
4
4
4
Browse the problem library