To determine what fraction of an hour 40 minutes represents, we start by noting that an hour is equivalent to 60 minutes.
We can express 40 minutes as a fraction of 60 minutes:
Fraction = (40 minutes) / (60 minutes)
This simplifies to:
Fraction = 40/60
Next, we can simplify the fraction by dividing both the numerator and the denominator by the greatest common divisor (GCD) of 40 and 60, which is 20:
Fraction = (40 ÷ 20) / (60 ÷ 20) = 2/3
Therefore, 40 minutes is 2/3 of an hour.