if 25 ml of sugar is mixed with 299 ml of water and then 50 ml of water is poured out, how much sugar remains in the 150 ml of wtare?

Answer 1

assuming that adding the sugar does not change the volume of the fluid, and assuming that you meant 200ml, since 50+150=200,

50ml is 1/4 of the fluid.
So, 1/4 of the sugar is poured out, leaving 3/4*25 = 18.75 ml.