Answer:
1/2 L
Step-by-step explanation:
She makes 1 1/2 L of lemonade i.e. 3/2 L of lemonade.
She pours 1/4 of liter of lemonade into a thermos to take to the park. The amount of lemonade left is:
3/2 - 1/4 = 1 1/4 L = 5/4 L
Her brother drinks 2/5 of the remaining lemonade. The amount of lemonade that her brother drinks is:
2/5 * 5/4 = 1/2 L
Her brother drinks 1/2 L.
5x4x2
320
go backwards, 75 + 45 = 120
120 * 5/3 = 200
200+40 = 240
240 *4/3 = 320