Average Of Three

Average Of Three

Write a function that averages three numbers.

average_of_three(a, b, c)

Return (a + b + c) / 3, rounded to 2 decimal places.

Examples

average_of_three(1, 2, 3)     // → 2.0
average_of_three(10, 20, 30)  // → 20.0
average_of_three(5, 5, 6)     // → 5.33

Walkthrough

Thinking it through

def average_of_three(a, b, c):
    return round((a + b + c) / 3, 2)

The parentheses around (a + b + c) matter for the same reason they did in Fahrenheit To Celsius: without them, Python's operator precedence would divide c by 3 first and then add a + b, which is a completely different (and wrong) computation.

/ in Python always performs true division and returns a float, so (1 + 2 + 3) / 3 gives 2.0, not 2 — that's why the average of three whole numbers can still come out with a decimal point. round(x, 2) then caps the result at two decimal places, which matters once the division doesn't divide evenly — (5 + 5 + 6) / 3 is 5.333333..., and round(..., 2) turns that into a clean 5.33.

main.py
Console
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