Answer:
12 students play chess
and 25 students play Sudoku
Explanation:
There are 30 students in Ms Barclay's classroom.
2/5 students play chess.
i.e.
play chess
i.e. 12 students play chess
5/6 of the students play Sudoku.
i.e.
play Sudoku
i.e. 25 students play Sudoku
Hence, 12 students play chess
and 25 students play Sudoku