1 1
2 3
3 6
4 10
5 15
6 21
7 28
8 36
9 45
10 55
11 66
12 78
13 91
14 105
15 120
16 136
17 153
18 171
19 190
20 210
21 231
22 253
23 276
24 300
here is a spreadsheet to help you understand the stair problem notice for 1 step 1 block, 2 step, 3 block, 3 step, 6 block and so on notice the blocks for the number of a step is that step plus all the other blocks needed to make all the one(s) below it. Notice it takes 105 blocks to make 14 steps.
So if you are familiar with the summation process you would add the number that go with that stair with all the stairs below it. example step 5 blocks would be 5 + 4 + 3 + 2 +1 or 15 blocks. I hope this gets you started. The second part I do not understand the problems because they are not equations. NO equal signs
glad if it helps
