Question

A brilliant question-


This is very interesting question.

Answer 1

1kg is the answer I think so

Answer 2

The whole thing weighs 1 kg including water and glass
Now half of the water is removed making the whole system to weigh 3/4 .. it means it has lost some weigh how much ?
1-3/4 = it has lost 1/4 kilogram thus emptying The half glass accounts for 1/4 kg then full will account for 1/2 kg thus now 1-1/2 = 1/2 kg

Or you can do maths also
Let the weight of glass be x kg
And that of water be y kg
X+Y = 1 kg
X+1/2Y= 3/4kg
SUBTRACT THEM
1/2 Y = 1/4
Thus giving you the value of y as 1/2 kg
Substituting y in equation 1 we get
X+1/2= 1
Also now. . giving us 1/2 kg