Calculate the total area of Mr. Bintum's house, which is composed of a semicircle, a rectangle, and a triangle.

Here are the solutions to the problems.

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a) Find the area of Mr. Bintum's house.

Step 1: Calculate the area of section A (semicircle).
The diameter of the semicircle is $14\text{m}$, so the radius $r = \frac{14\text{m}}{2} = 7\text{m}$.
The area of a semicircle is given by $A_A = \frac{1}{2}\pi r^2$. We will use $\pi \approx 3.14$.

$$A_A = \frac{1}{2} \times 3.14 \times (7\text{m})^2$$ $$A_A = \frac{1}{2} \times 3.14 \times 49\text{m}^2$$ $$A_A = 1.57 \times 49\text{m}^2$$ $$A_A = 76.93\text{ m}^2$$

Step 2: Calculate the area of section B (rectangle).
The length of the rectangle is $20\text{m}$ and the width is $14\text{m}$.
The area of a rectangle is given by $A_B = \text{length} \times \text{width}$.

$$A_B = 20\text{m} \times 14\text{m}$$ $$A_B = 280\text{ m}^2$$

Step 3: Calculate the area of section C (triangle).
The height of the triangle is $3\text{m}$ and the hypotenuse is $5\text{m}$. First, find the base using the Pythagorean theorem ($a^2 + b^2 = c^2$).
Let the base be $b$.

$$b^2 + (3\text{m})^2 = (5\text{m})^2$$ $$b^2 + 9\text{m}^2 = 25\text{m}^2$$ $$b^2 = 25\text{m}^2 - 9\text{m}^2$$ $$b^2 = 16\text{m}^2$$ $$b = \sqrt{16\text{m}^2}$$ $$b = 4\text{m}$$

The area of a triangle is given by $A_C = \frac{1}{2} \times \text{base} \times \text{height}$.

$$A_C = \frac{1}{2} \times 4\text{m} \times 3\text{m}$$ $$A_C = 6\text{ m}^2$$

Step 4: Calculate the total area of Mr. Bintum's house.
Total Area = $A_A + A_B + A_C$

$$\text{Total Area} = 76.93\text{ m}^2 + 280\text{ m}^2 + 6\text{ m}^2$$ $$\text{Total Area} = 362.93\text{ m}^2$$

The area of Mr. Bintum's house is $\boxed{\text{362.93 m}^2}$.

b) Find how much Mr. Bintum will spend if he decides to put tiles on the floor of the kitchen at the cost of 2500 FRS per m$^2$.

Step 1: Identify the area of the kitchen.
The kitchen is section C, which has an area of $6\text{ m}^2$.

Step 2: Calculate the total cost of tiling.
Cost = Area of kitchen $\times$ Cost per m$^2$

$$\text{Cost} = 6\text{ m}^2 \times 2500 \text{ FRS/m}^2$$ $$\text{Cost} = 15,000 \text{ FRS}$$

Mr. Bintum will spend $\boxed{\text{15,000 FRS}}$ to tile the kitchen.

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Find the cost of painting the walls at 200 FRS per square meter.

Step 1: Calculate the total area of the walls.
The party hall measures $20\text{m}$ long, $18\text{m}$ wide, and $8\text{m}$ high.
Area of two walls (length $\times$ height) = $2 \times (20\text{m} \times 8\text{m})$

$$2 \times 160\text{ m}^2 = 320\text{ m}^2$$

Area of two walls (width $\times$ height) = $2 \times (18\text{m} \times 8\text{m})$

$$2 \times 144\text{ m}^2 = 288\text{ m}^2$$

Total wall area = $320\text{ m}^2 + 288\text{ m}^2 = 608\text{ m}^2$.

Step 2: Calculate the area of the doors and windows.
There are two large doors, each measuring $3\text{m}$ by $2\text{m}$.
Area of two doors = $2 \times (3\text{m} \times 2\text{m})$

$$2 \times 6\text{ m}^2 = 12\text{ m}^2$$

There are four large windows, each measuring $4\text{m}$ by $4\text{m}$.
Area of four windows = $4 \times (4\text{m} \times 4\text{m})$

$$4 \times 16\text{ m}^2 = 64\text{ m}^2$$

Total area of doors and windows = $12\text{ m}^2 + 64\text{ m}^2 = 76\text{ m}^2$.

Step 3: Calculate the area to be painted.
Area to be painted = Total wall area - Area of doors and windows

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