The expression you’ve written, 11 15/20, represents a mixed number. To convert it to a proper fraction or decimal, follow these steps:

Step 1: Convert the mixed number to an improper fraction.

A mixed number consists of a whole number and a fraction. Here, the whole number is 11, and the fraction is 15/20.

To convert it:

1. Multiply the whole number by the denominator of the fraction:
   $11 \times 20 = 220$
2. Add the numerator of the fraction:
   $220 + 15 = 235$
3. Therefore, the improper fraction is:
   $\frac{235}{20}$

Step 2: Simplify the improper fraction (if possible).

We can simplify $\frac{235}{20}$ by finding the greatest common divisor (GCD) of 235 and 20. The GCD of 235 and 20 is 5.

Now, divide both the numerator and the denominator by 5: $\frac{235 \div 5}{20 \div 5} = \frac{47}{4}$

Step 3: Convert the improper fraction to a decimal.

To convert $\frac{47}{4}$ to a decimal, simply divide 47 by 4: $47 \div 4 = 11.75$

So, 11 15/20 = 11.75.

Would you like more details or help with another concept?

Here are some related questions:

1. How do you convert a mixed number to a decimal?
2. What is the process for simplifying fractions?
3. How do you convert a decimal to a fraction?
4. What is the GCD, and how do you find it?
5. How can you convert a fraction to a percentage?

Tip: Always simplify fractions to their lowest terms before working with them in calculations.