Draw a bar model: Total = 660 L stays constant.
After: B = 1 unit, A = 3 units. Total = 4 units = 660 L.
1 unit = 165 L. Transfer from A to B = 165 - 30 = 135 L.AGS Rule Box
| Total water | = | 630 + 30 = 660 L |
| After: 1 unit (B) | = | 660 / 4 = 165 L |
| Transfer from A | = | 165 - 30 = 135 L |
Final Answer: 135