The requirements should be on the individual university
websites
i.e. for NUS
http://www.nus.edu.sg/oam/apply/local/prerequisites/BYA-prerequisites.html
Business Administration H1 pass in Mathematics or pass in 'O'
Level Additional Mathematics.
Business Administration (Accountancy) H1 pass in Mathematics or
pass in 'O' Level Additional Mathematics.
Business Analytics H2 pass in Mathematics