Question

In a survey, 200 students were asked what influenced them most to buy their latest CD. The results are shown in the circle graph.

1. How many students said radio influenced them most?
2. How many more students were influenced by radio than by a music video channel?
3. How many said a friend or relative influenced them or they heard the CD in a shop?

Answer 1

a. Fraction of radio (in figure) = `9/20`

Total number of students = 200

∴ Number of students influenced by radio the most `9/20` of 200

= `9/20 xx 200`

= 90

b. We have to find,

(Students influenced by radio) – (Students influenced by music video channel)

= (Fraction of radio × Total number of students) – (Fraction of music video channel × Total number of students)

= `9/20` of `200 - 2/25` of 200

= `9/20 xx 200 - 2/25 xx 200`

= 90 –  16

= 74

Hence, 74 more students were influenced by radio than by a music video channel.

c. We have to find,

(Students who were influenced by a friend or relative) + (Students who were influenced by hearing songs in the shop)

= `3/20` of `200 + 1/10` of 200

= `3/20 xx 200 + 1/10 xx 200`

= 30 + 20

= 50