AMO 2021 — Secondary 1 (Grade 7) Question 5

Question 5

Four numbers $P,Q,R,S$ are in ascending order. The average of $P,Q,R$ is 22, and the average of $Q,R,S$ is 24. The largest number is 27. Which statement describes the smallest number?

Question illustration

It is prime
It is a multiple of 9
It is a multiple of 11
It is a multiple of 7
It cannot be determined