Answer:
The students would be expected to choose rock be<u> 80</u> or students choose hip hop be <u>160</u> or choose to country be <u>120</u>.
Step-by-step 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
Let the number of students expected to choose hip hop be
Let the number of students expected to choose country be
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 .
<u><em>Thus, the number of students expected to choose rock is 80.</em></u>
Now,
In a survey of 90 students 40 choose hip hop.
So, 90 is equivalent to 40.
Thus, 360 is equivalent to
<u><em>Therefore, 160 students expected to choose hip hop.</em></u>
And,
In a survey of 90 students 30 choose country.
So, 90 is equivalent to 30.
Thus, 360 is equivalent to
<u><em>Hence, 120 students expected to choose country.</em></u>
Therefore, the students would be expected to choose rock be 80 or students choose hip hop be 160 or choose to country be 120.