Question

A tank weighs 5.6kg when it 1/4 filled with water.If it weighs 10.4kg when it is full ,what will be it's weight when it is empty.​

Answer 1

4 kg

Step-by-step explanation:

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Answer 2

4 kg

Step-by-step explanation:

Let the mass of tank be 't' and water 'w'

First equation : (when it is 1/4 filled with water)

• 
  `\sf t + (1)/(4) w = 5.6`

Second equation : (when it is filled fully with water)

• 
  `\sf t +w = 10.4`

• 
  `\sf w = 10.4 - t`

Insert second equation into first equation :

`\rightarrow \sf t + (1)/(4) (10.4 - t) = 5.6`

`\rightarrow \sf t - (1)/(4) t + 2.6 = 5.6`

`\rightarrow \sf (3)/(4) t = 5.6 - 2.6`

`\rightarrow \sf (3)/(4) t = 3`

`\rightarrow \sf t = 4`

The tank weights 4 kg when it is empty.