Math Problem (Level 1) : Same depth of the water in the vessel (K3)

There is water to a depth of 10 cm in A.

When the water of A is put into B and it is the same depth of the water of A and B, what cm is the depth of the water?






Answer
6 cm

Solution
The volume of water is divided by the sum of the base area of A and B, then you can find the depth of water. 
The volume of water is 10 x 15 x 10 = 1500 cm3, the sum of the base area of A and B is 10 x 15 + 10 x 10 = 250 cm2
The depth of water is 1500/250 = 6 (cm).