Question

In Mr. Senter's classroom, 2/3 of the students play sudoku. Of the students who play sudoku, 3/8 also play chess. If there are 24 students in his class, how many play sudoku and chess?how did she get 9

Answer 1

The number of students given are 24.

The students who play sudoku is,

$\frac{2}{3}\times24=16.$

Out of the students who play sudoku , the students who play chess are

$16\times\frac{3}{8}=6.$

Therefore the students who play sudoku are 16 and play chess are 6.

The number of students who play both chess and sudoku is,

$\text{ n}(C\cup S)=n(C)+n(S)-n(C\cap S)$

Substitute the values,

$24=16+6-n(C\cap S)$$n(C\cap S)=24-22$$n(C\cap S)=2.$

Thus , the number of students who play both chess and sudoku is, 2.