Karen ran for 1-half hour. Her brother ran for 2-fifths hour.
How much longer, in hours, did Karen run than her brother?
To determine how much longer Karen ran than her brother, we need to subtract the length of time that her brother ran from the length of time that Karen ran.
Karen ran for 1/2 hour.
Her brother ran for 2/5 hour.
The difference between the two is 1/2 - 2/5.
To subtract fractions, we need to find a common denominator. The common denominator for 2 and 5 is 10.
1/2 = 5/10 and 2/5 = 4/10.
Therefore, 1/2 - 2/5 = 5/10 - 4/10 = 1/10.
Therefore, Karen ran 1/10 hour longer than her brother.