At the beginning of the week, the temperature was 15. During the week, it decreased by 20. What was the temperature by the end of the week? What is the percent Change of the weekly temperature? Show work​

I’m confused on how to work the pie charts

12 out of 30 people chose their favourite colour as blue caculate the angle you would use for blue on a pie chart

Solve the problem by using a venn diagram a group of students were surveyed about their taste in music.they were asked how they like three types of music: rock, country western and jazz.the results are summarized below: no one dislikes all three types of music.six like all three types of music.eleven don’t like country western.sixteen like jazz.three like country western and jazz, but not rock.six don’t like rock.eight like rock and country western.seven don’t like jazz.how many students were surveyed?