Adding and Subtracting fractions

What is the common denominator in question 1? What is the answer?

• 15 and 4/15

• 9 and 7/9

• 10 and 9/10

• 15 and 11/15

What is the common denominator in question 2?

What is the second numerator of question 2?

What is the answer to question 2?

What are the two fractions in question 3?

What is the answer to question 4?

• 15/18

• 8/10

• 11/18

• 4/5