Let's convert each of the given rational numbers to decimal form.

(i) $\frac{42}{100}$: $\frac{42}{100} = 0.42$ So, $\frac{42}{100} = 0.42$.

(ii) $\frac{327}{500}$: To convert this fraction to decimal, divide 327 by 500: $\frac{327}{500} = 0.654$ So, $\frac{327}{500} = 0.654$.

(iii) $\frac{15}{4}$: To convert this fraction to decimal, divide 15 by 4: $\frac{15}{4} = 3.75$ So, $\frac{15}{4} = 3.75$.

Summary:

• $\frac{42}{100} = 0.42$
• $\frac{327}{500} = 0.654$
• $\frac{15}{4} = 3.75$

Would you like more details or explanations on any of these?

Here are some related questions:

1. How do you convert a fraction to a decimal?
2. What is a terminating decimal and how does it relate to rational numbers?
3. How would you convert a repeating decimal into a fraction?
4. What are rational and irrational numbers?
5. How do you simplify fractions before converting them to decimals?

Tip: When converting fractions to decimals, always try dividing the numerator by the denominator to get the decimal form directly.