Arithmetic Progression problem:---- We have to arrange 100 marbles in increasing order of rows, starting with one, then two and so on . How many rows will be complete and how many marbles will be left ...
1 in 1 row
3 total in 2 rows
6
10
15
21
28
36
45
55
66
78
91 with 13 rows complete, 9 marbles left over