MathDB
Problems
Contests
National and Regional Contests
India Contests
India Pre-Regional Mathematical Olympiad
2017 India PRMO
6
6
Part of
2017 India PRMO
Problems
(1)
2017 preRMO p6, \sum_{n=1}^{9} \1/n(n+1)(n+2)
Source:
8/9/2019
Let the sum
∑
n
=
1
9
1
n
(
n
+
1
)
(
n
+
2
)
\sum_{n=1}^{9} \frac{1}{n(n+1)(n+2)}
∑
n
=
1
9
n
(
n
+
1
)
(
n
+
2
)
1
written in its lowest terms be
p
q
\frac{p}{q}
q
p
. Find the value of
q
−
p
q - p
q
−
p
.
Sum
algebra