+312 Find the sum of all positive integers less than 1000 ending in 3 or 4 or 5.
+1804 First, let's note that
\(3 + 4 + 5 = 3 *4\)
\(13 + 14 + 15 = 3 * 14\)
This pattern will keep going. Thus, we just have
\(3 [ 4 + 14 + 24 + ....... + 994 ]\)
No. of terms = 100
Thus, our final answer is
\(3 [ 994 + 4 ] [ 100 / 2 ] = 149,700\)
Thanks! :)
