A box weighs 8.5 kg when full of sand and weighs 5.5 kg when it is half filled with sand. Weight of the empty box is
1
5 kg
2
6 kg
3
2.5 kg
4
4.5 kg
A box weighs 8.5 kg when full of sand and weighs 5.5 kg when it is half filled with sand. Weight of the empty box is