A tank with rectangular base and rectangular sides, open at the top is to be constructed so that its depth is 2 m and volume is 8 m3. If building of tank costs Rs 70 per square metre for the base and Rs 45 per square metre for sides, what is the cost of least expensive tank?

Explanation

To solve the problem of finding the cost of the least expensive tank, we will follow these steps:

### Step 1: Define the variables
Let:
- \( L \) = length of the tank (in meters)
- \( B \) = breadth of the tank (in meters)
- \( H \) = height of the tank = 2 m (given)
- Volume of the tank = \( L \times B \times H = 8 \, \text{m}^3 \)
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