Answer:
Increment of 3:
1. first of all enter values in first two cell with gap of three i.e(enter 3 in first cell and 6 in second cell of same column).
2. Select both cell
3. expand the your cell selection from bottom right edge of selection till the cell you want to auto fill with increment of 3
Decrements of 5:
1. first of all enter values in first two cell with gap of 5 in decreasing order i.e(enter 1000 in first cell and 995 in second cell of same column).
2. Select both cell
3. expand the your cell selection from bottom right edge of selection till the cell you want to auto fill with decrements of 5
Note: proper image of selection and expansion are attached bellow :
Explanation:
