Data Sufficiency

At the beginning of the year, the Finance Committee and the planning committee of a certain company each had n members, and no one was a member of both committees. At the end of the year, 5 members left the Finance Committee and 3 members left the planning Committee. How many members did the Finance Committee have at the beginning of the year?

1. The ratio of the total number of members who left at the end of the year to the total number of members at the beginning of the year was 1:6.
2. At the end of the year, 21 members remained on the Planning Committee.

OA-> D

Hi expert.
Could you please explain to me why the statement 2 is sufficient?

John fran kennedi wrote:At the beginning of the year, the Finance Committee and the planning committee of a certain company each had n members, and no one was a member of both committees. At the end of the year, 5 members left the Finance Committee and 3 members left the planning Committee. How many members did the Finance Committee have at the beginning of the year?

1. The ratio of the total number of members who left at the end of the year to the total number of members at the beginning of the year was 1:6.
2. At the end of the year, 21 members remained on the Planning Committee.

OA-> D

Hi expert.
Could you please explain to me why the statement 2 is sufficient?

The question states that each committee had n members at the beginning of the year, meaning that at the beginning of the year the number of members of the Planning Committee was equal to the number of members of the Finance Committee.

Since by adding the 21 in Statement 2 to the 3 in the question you can determine the number of members on the Planning Committee at the beginning of the year, you can also determine the number of members on the Finance Committee at the beginning of the year.

Ok, I now understand perfectly . Thank you so much