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A jug filled with water weight 2kg 450g. When the jug is 1/5 filled with water, it weights 1.05 kg.
What is the mass of the jug when it is half filled with water?
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J + W = 2450, (1) (J = jug's weight; W = water weight when jug is filled).
J + 0.2W = 1050. (2)
To solve the system, distract (2) from (1). You will get
0.8W = 2450 - 1050, or
0.8W = 1400 ---> W = = 1750 grams.
Thus water weights 1750 gram when the jug is full.
Now, the answer to the problems is 2450 -
(jug filled with water minus half of 1750 grams of water).
Can you calculate it on your own?