Can Mary safely water a plant if it must be watered with exactly 6 liters of water exactly once a day from only one vessel and all she has is a 5-liter jug and a 7-liter jug?

Answer 1

1. Fill 5L vessel and pour all 5L into 7L vessel. 2. Fill 5L vessel again and fill the remainder of the 7L vessel (2L...leaving you with 3L in 5L vessel) 3. Empty 7L vessel and pour the 3L from 5L vessel into 7L vessel. 4. Fill 5L vessel again and fill the remainder of the 7L vessel (this will be 4L, as you have already got 3L in 7L vessel from Step 3. Leaving you with 1L in 5L vessel) 5. Empty the 7L vessel. Pour the 1L (from Step 4) from the 5L vessel into the 7L vessel. 6. Fill the 5L vessel and add it to the 1L (from step 5) in the 7L vessel. You now have 6L in the 7L vessel...WATER THE PLANT!
1 Kg or 1000 grams