+415 Find the sum of all positive integers less than $1000$ ending in $3$ or $4$ or $5$.
+1365 To complete this problem, we must make an important observation.
NOTE:
\(3 + 4 + 5 = 3 *4 \\ 13 + 14 + 15 = 3 * 14\)
Now, we just have to figure out \(3 [ 4 + 14 + 24 + ....... + 994 ] = \)
There are 100 terms in the sequence, so we have
\(3 [ 994 + 4 ] [ 100 / 2 ] = 149,700\).
Thanks! :)
+1365 To complete this problem, we must make an important observation.
NOTE:
\(3 + 4 + 5 = 3 *4 \\ 13 + 14 + 15 = 3 * 14\)
Now, we just have to figure out \(3 [ 4 + 14 + 24 + ....... + 994 ] = \)
There are 100 terms in the sequence, so we have
\(3 [ 994 + 4 ] [ 100 / 2 ] = 149,700\).
Thanks! :)
