Lisa and kyle have to clean their bedrooms. kyle cleans his room in 1 2/5 hours. lisa cleans her room in 2 1/4 hours. how many hours longer does it take lisa to clean her room than kyle ? ?

The answer is 1 3/20
you find this answer by making the denominator of the fractions the same.
you do that by least common multiple, which is 20. then you would have to convert the fractions to the denominator and multiply the numerator by the number you multiplied with the old denominator. We would get 8/20 and 5/20. next, you subtract the numerators only, which is 3. then you subtract the mixed numbers which are 2 and 1 which is 1. Combine the mixed number and the fraction, and you'll get 1 3/20