1: 2: divide 18 apples equally into 3 portions, each portion accounting for () of the total number, and 2 portions accounting for (). Do you find the difference between the above two questions? Please tell me

1: 2: divide 18 apples equally into 3 portions, each portion accounting for () of the total number, and 2 portions accounting for (). Do you find the difference between the above two questions? Please tell me

1/3
2/3
1/3
2/3
The unit "1" is different