Answer :
The membership increased from 20 to 30.
That's an increase of 10 members.
10 members is how much of the original 20 ?
10 members is HALF of the original 20.
The membership increased by HALF.
The membership increased by 50% .
The membership increased from 20 to 30.
That's an increase of 10 members.
10 members is how much of the original 20 ?
10 members is HALF of the original 20.
The membership increased by HALF.
The membership increased by 50% .