Answer :
1 L = 1000 mL
1800mL=1.8L
she needs 3 L which is 3000 mL.
so she needs 1.2 L which is 1200 mL after the 1800mL
1800mL=1.8L
she needs 3 L which is 3000 mL.
so she needs 1.2 L which is 1200 mL after the 1800mL