Answer:
1/2 liters
Explanation:
Rosanne makes 1 1/2 liters of strawberry lemonade
She pours 1/4 of the lemonade into a thermos
The quantity left is
= 1 1/2 - 1/4
= 3/2 - 1/4
= 5/4
Her brother drinks 2/5 of the remaining lemonade
Therefore the quantity of lemonade that Rosanne brother drinks can be calculated as follows
= 2/5 × 5/4
=1/2
Hence the quantity of lemonade that Rosanne brother drinks is 1/2 liters