every morning, halle goes to school with 1 liter bottle of water. she drinks 1/4 of the bottle before school starts and 2/3 of the rest before lunch.

The question doesn't have any requirement. I'll calculate the water Halle has left for lunch after drinking the rest.

Answer:

Halle has 250 ml of water for lunch

Step-by-step explanation:

Fractions and Proportions

Fractions often express ratios between partial and total measures. In this context, 1/4 means 1 part out of 4 parts.

Halle goes to school with 1 liter of water in a bottle, she drinks 1/4 of the bottle before school starts. The bottle now has 3/4 of a liter of water

Halle drinks 2/3 of it before lunch, it means that the bottle has 1/3 of 3/4 left of the water. Since 1/3*3/4 = 1/4. That is the fraction of water still present in the bottle.

Since 1 liter is 1000 ml, Halle has 1/4*1000 = 250 ml of water for lunch