Answer:
11
It is the only number that can only be multiplied by itself and 1 to itself
9 can be multiplied by 3 x 3 = 9 so it isn't prime
10 can be multiplied by 5 x 2 = 10 so it isn't prime
12 can be multiplied by 3 x 4 = 12 so it isn't prime
Hope this helps
Step-by-step explanation:
