A wooden bookshelf has external dimensions as follows: `H e igh t=110c m ,D e p t h=25 c m ,B r e a dt h=85 c m` (See Figure). The thickness of the plank is `5c m` everywhere. The external faces are to be polished and the inner face are to be painted. If the rate of polishing is `20 p a i s e p e r c m^2` and if the rate of painting is `10 paise per cm^2`. Find total cost of expenses.

Explanation

To solve the problem step by step, we will calculate the total cost of polishing the external faces and painting the internal faces of the wooden bookshelf.

### Step 1: Identify External Dimensions
- Height (H) = 110 cm
- Depth (D) = 25 cm
- Breadth (B) = 85 cm
- Thickness of the plank (t) = 5 cm

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