Step-by-step explanation:

So what you'll do is add the hours all three girls spent

5 1/3 + 5/3 + 5 4/3= n

First, add the whole numbers so that it will be easier later

5+5= 10

Second, gather the fractions

1 + 5 + 4

3 3 3

Third, add all the numerators

1 + 5 + 4= 10

3 3 3

Fourth, copy the denominator since it is similar fractions

1 + 5 + 4= 10

3 3 3 3

Fifth, turn your improper fraction into mixed fraction

10= 3 1/3

3

Sixth, add all the whole numbers

3+ 10=13

Lastly, combine the whole number with the fraction

13 1/3

:. Therefore, the total hours the three girls spent studying their lessons is 13 1/3 hours.

I HOPE THIS HELPS:))