#6
Given:

Asked: Find the missing denominator.
Solution:
To find the missing denominator, we need to know what was multiplied to 2 that became 8.
We can then multiply the factor to 5 to get the missing denominator.
To find the factor, we will divide the numerators:

The factor is 4. Now we will multiply 4 to the denominator 5 to get the missing denominator.

ANSWER: 20