Kareem took 4 2/5 hours to clean the bathroom. Then he took 2 1/4 hours to clean the den. How much total time did Kareem take to clean the two rooms?

Write your answer as a mixed number in simplest form.

6 13/20 hours

Step-by-step explanation:

Addition of fractions requires they be expressed using a common denominator. Here, that will be 5·4 = 20, and the two fractions can be written as ...

2/5 = 8/20

1/4 = 5/20

Then the sum of the mixed numbers is ...

(4 2/5) + (2 1/4) = (4 + 2) + (2/5 + 1/4) = 6 + (8/20 + 5/20)

= 6 13/20

It took Kareem 6 13/20 hours to clean the two rooms.