Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
The value of the sum
∑
k
=
1
∞
∑
n
=
1
∞
k
2
n
+
k
\sum_{k=1}^{\infty} \sum_{n=1}^{\infty} \frac{k}{2^{n+k}}
∑
k
=
1
∞
∑
n
=
1
∞
2
n
+
k
k
is equal to: (a) 5 (b) 4 (c) 3 (d) 2
Browse the problem library