1 + 2 + 3 + ⋯ + 2 0 1 7 1 2 + 2 2 + 3 2 + ⋯ + 2 0 1 7 2 = ?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
How can you simplify it to that?
Log in to reply
The first expression is of the form :
1
2
+
2
2
+
3
2
+
⋯
+
n
2
=
6
n
(
n
+
1
)
(
2
n
+
1
)
& the second one being
1
+
2
+
3
+
⋯
+
n
=
2
n
(
n
+
1
)
. Now put n= 2017 to get the desired result.
Problem Loading...
Note Loading...
Set Loading...
Clearly the expression Can be simplified to - 2 2 0 1 7 . 2 0 1 8 6 2 0 1 7 ( 2 0 1 8 ) ( 4 0 3 5 ) = 3 4 0 3 5 . again don't divide it . we have only 1 option having unit's digit 5. So that's the answer indeed.