What is the average of first 25 multiples of 5?

Sure, let's calculate the average of the first 25 multiples of 5.

Step 1: Identify the first 25 multiples of 5. They are: 5, 10, 15, 20, ..., 120, 125.

Step 2: The formula to find the average (mean) of a set of numbers is: (Sum of all numbers) / (Total number of numbers)

Step 3: Since these numbers form an arithmetic progression, we can use the formula for the sum of an arithmetic series to find the sum of these numbers. The formula is: Sum = n/2 * (a + l) where n is the number of terms, a is the first term, and l is the last term.

Step 4: Substituting the values into the formula, we get: Sum = 25/2 * (5 + 125) = 1625

Step 5: Now, we can find the average by dividing the sum by the total number of terms: Average = Sum / n = 1625 / 25 = 65

So, the average of the first 25 multiples of 5 is 65.