Complex sentence: The Senate has 66 members; 50 are elected for five-year terms by single-member constituencies; of the remaining 16 seats, 6 are appointed and 10 are elected chiefs.
Split into simpler sentences: The Senate has 66 members: 50 of whom are elected for five-year terms by single-member constituencies. Of the remaining 16 seats, 6 are appointed and 10 are elected chiefs.