Average of Three Numbers Problem

Suppose you have three different bills:

• $20
• $30
• $50

You want to know the average amount of money you have across all three bills.

Solution

Let a = $20, b = $30, and c = $50. Then, the sum of these three numbers is X = $20 + $30 + $50 = $100.

Using the Average of Two Numbers Theorem, we can calculate the averages of the first two numbers and the last two numbers:

• W = (a + b) / 2 = ($20 + $30) / 2 = $25
• P = (b + c) / 2 = ($30 + $50) / 2 = $40

Finally, we can calculate the overall average of the three bills by averaging the values of W and P:

(Average amount) = (W + P) / 2 = ($25 + $40) / 2 = $32.50

Therefore, the average amount of money you have across all three bills is $32.50.