Question

In a survey of 90 students 20 choose rock.40 chose hip hop 30 chose country. In a school of 360 students how many would be expected to chose hip hop or rock

Answer 1

The students would be expected to choose rock be 80 or students choose hip hop be 160 or choose to country be 120.

Explanation:

Given:

In a survey of 90 students 20 choose rock, 40 choose hip hop and 30 choose country.

Now, to find the students expected to choose hip hop or rock or country in a school of 360 students.

Let the number of students expected to choose rock be
`x.`

Let the number of students expected to choose hip hop be
`y.`

Let the number of students expected to choose country be
`z.`

Total number of students = 360.

Now, to get the number of students choosing hip hop or rock or country by using cross multiplication method:

In a survey of 90 students 20 choose rock.

So, 90 is equivalent to 20.

Thus, 360 is equivalent to
`x`.

`(90)/(20) =(360)/(x) \\\\By\ cross\ multiplying\ we\ get:\\\\90x=7200\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\x=80.`

Thus, the number of students expected to choose rock is 80.

Now,

In a survey of 90 students 40 choose hip hop.

So, 90 is equivalent to 40.

Thus, 360 is equivalent to
`y.`

`(90)/(40) =(360)/(y) \\\\By\ cross\ multiplying\ we\ get:\\\\90y=14400\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\y=160.`

Therefore, 160 students expected to choose hip hop.

And,

In a survey of 90 students 30 choose country.

So, 90 is equivalent to 30.

Thus, 360 is equivalent to
`y.`

`(90)/(30) =(360)/(z) \\\\By\ cross\ multiplying\ we\ get:\\\\90x=10800\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\x=120.`

Hence, 120 students expected to choose country.

Therefore, the students would be expected to choose rock be 80 or students choose hip hop be 160 or choose to country be 120.