Question 21
Three sisters, Catherine, Stacy, and Fiona, were talking about their ages.
Catherine said, “I am 16 years old. I am younger than Stacy by 3 years. I am older than Fiona by 2 years.”
Stacy said, “I am not the youngest. The difference between my age and Fiona’s age is 5 years. Fiona is 21 years old.”
Fiona said, “I am younger than Catherine. Catherine is 18 years old. Stacy is younger than Catherine by 3 years.”
If exactly two sentences in each sister’s statement are correct, how old is Fiona?
Answer format: enter one whole number without units; leading zeros are optional. The source answer sheet uses four digits (for example, 7 is shaded as 0007).
Catherine said, “I am 16 years old. I am younger than Stacy by 3 years. I am older than Fiona by 2 years.”
Stacy said, “I am not the youngest. The difference between my age and Fiona’s age is 5 years. Fiona is 21 years old.”
Fiona said, “I am younger than Catherine. Catherine is 18 years old. Stacy is younger than Catherine by 3 years.”
If exactly two sentences in each sister’s statement are correct, how old is Fiona?
Answer format: enter one whole number without units; leading zeros are optional. The source answer sheet uses four digits (for example, 7 is shaded as 0007).