| Start | Finish | |
| Selena | 500 | 620 |
| Ella | 600 | 480 |
Hi
Selena and Ella shared a sum of money. When Selena's share increased from 500 to 620 dollars, the amount of Ella's share decreased by 20%. How much was Ella's share at first.
Let Ella's ORIGINAL/Old amount be E
Then Ella's NEW/Altered amount = E - 120
Ella's NEW/Altered amount decreased by 20%, or from 100% to 80% (.8)
We then get: E - 120 = .8E
- 120 = .8E - E
- 120 = - .2E
Original/Old amount Ella had, or