Answer:
12 students play chess
and 25 students play Sudoku
Step-by-step explanation:
There are 30 students in Ms Barclay's classroom.
2/5 students play chess.
i.e. [tex]\dfrac{2}{5}\times 30[/tex] play chess
i.e. 12 students play chess
5/6 of the students play Sudoku.
i.e. [tex]\dfrac{5}{6}\times 30[/tex] play Sudoku
i.e. 25 students play Sudoku
Hence, 12 students play chess
and 25 students play Sudoku