Question 1207330
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It's awkward to discuss the problem without units, so I will assume the given dimensions are centimeters.<br>
The volume of water is the volume of container A, which is 40*25*30 = 30,000 cm^3.<br>
Let x be the height (depth) of the water in the two containers after some of it is poured into container B.
Then the volume of water in container A is (25*30)*x = 750x
And the volume of water in container B is (25*18)*x = 450x<br>
The volume of water in the two containers is the original 30,000 cm^3:<br>
{{{750x+450x = 30000}}}
{{{1200x=30000}}}
{{{x=30000/1200=25}}}<br>
ANSWER: 25cm<br>