A rectangular water tank is 90cm wide and 40cm deep. If it can contain 576 litres of water, what is its length?
Let the length of the rectangular tank be l cm.
Given its width is 90 cm, and depth is 40 cm.
Now the volume of the rectangular tank is 90×40×l=3600l cm3.
Given it can hold 576 litres =576,000 cm3 of water.
Then
3600l=576,000
or,l=576036
or, l=160.
So length is 160 cm.