Solve the following decimal operations: a) 23.4 + 17.56, b) 45.7 - 18.92, c) 6.25 x 4. Then solve: a) 12.6 / 3, b) 45.5 / 5. Finally, convert decimals to fractions: a) 0.25, b) 0.6, c) 1.75.

$$23.4 + 17.56 = 40.96$$

The sum is $\boxed{\text{40.96}}$.

b)

$$45.7 - 18.92 = 26.78$$

The difference is $\boxed{\text{26.78}}$.

c)

$$6.25 \times 4 = 25.00$$

The product is $\boxed{\text{25}}$.

Question 4

a)

$$12.6 \div 3 = 4.2$$

The quotient is $\boxed{\text{4.2}}$.

b)

$$45.5 \div 5 = 9.1$$

The quotient is $\boxed{\text{9.1}}$.

Question 5

a)

$$\frac{25}{100} = \frac{25 \div 25}{100 \div 25} = \frac{1}{4}$$

The fraction is $\boxed{\frac{1}{4}}$.

b)

$$\frac{6}{10} = \frac{6 \div 2}{10 \div 2} = \frac{3}{5}$$

The fraction is $\boxed{\frac{3}{5}}$.

c)

$$1\frac{3}{4} = \frac{1 \times 4 + 3}{4} = \frac{7}{4}$$

The fraction is $\boxed{\frac{7}{4}}$.

Question 6

a)

$$\text{Cost of 4 packets} = \text{R}12.50 \times 4 = \text{R}50.00$$

The cost of 4 packets is $\boxed{\text{R}50.00}$.

b)

$$\text{Change received} = \text{R}100.00 - \text{R}50.00 = \text{R}50.00$$

The change received will be $\boxed{\text{R}50.00}$.