Half of the students of a class are dancing nd 3/4 of the remaining r playing cricket . if the remaning 9 students r studying in the library then find the total no. of students in class.

N = number of students

Half of the students of a class are dancing

D = ½

3/4 of the remaining play cricket

C = ¾(½N)

Y = students studying in the library

Y = ¼(½N)

If Y = 9,

¼(½N) = 9

½N = 9 * 4

½N = 36

N = 36 * 2

N = 72

There are 72 students in the class.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".