(7-1 5/9 : 1 1/3) • 1 7/20

To solve this expression, we first need to simplify the subtraction inside the parentheses:

7 - 1 = 6

Next, we need to convert the mixed numbers to improper fractions and then subtract:

5/9 * 3 = 15/9

1 1/3 = 4/3 4/3 - 15/9

Now, we need to find a common denominator:

4/3 = 12/9

12/9 - 15/9 = -3/9 = -1/3

Now, multiply the result by 1 7/20:

-1/3 * 27/20

To multiply fractions, multiply the numerators together and the denominators together:

(-127)/(320) = -27/60

Now, simplify the result if needed:

-27/60 = -9/20

Therefore, (7-1 5/9 : 1 1/3) • 1 7/20 = -9/20.