If only the positive integers from 1 through 49, inclusive, are written on a piece of paper, what is the sum of all the numbers that are written on the paper?
the same question was posted on Aug 26, 2018 by Lightning.
It was answered by deirdust (signed as Daisy) and she wrote-
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49
By the chart, you can see that there are:
Fifteen 1's
Fifteen 2's
Fifteen 3's
Fifteen 4's
Five 5's
Five 6's
Five 7's
Five 8's
Five 9's and
Four 0's (Of course, the zero's would not matter, because they are asking for the sum).
So we are trying to find s, the sum of the digits. We can get the equation s=15(1)+15(2)+15(3)+15(4)+5(5)+5(6)+5(7)+5(8)+5(9), which is equal to s=15+30+45+60+25+30+35+40+45, which we can finally get s=325
-Daisy
Hope this is helpfull!
-Abi
