Question

100 students are interviewed to see which of biology, chemistry or physics they prefer. 52 of the students are girls. 29 of the girls like biology best. 24 of the boys prefer physics. 13 out of the 21 who prefer chemistry are girls. What percentage of the students prefer biology?

Answer 1

Answer:

$45$ % of the students prefer biology.

Step-by-step explanation:

Let's read and write all the data from the question.

100 students are interviewed to see which of biology, chemistry and physics they prefer.

Therefore, we have three categories to classify the students :

A student that prefers biology

A student that prefers chemistry

And a student that prefers physics

52 of the students are girls. Therefore,

$100-52=48$ students are boys.

29 of the girls like biology best. In order to answer the question, we will only need the amount of boys that prefer biology and sum them to the amount of girls that like biology best.

24 of the boys prefer physics. Therefore,

$48-24=24$ is the sum of the boys that prefer chemistry and biology.

13 out of the 21 who prefer chemistry are girls. Therefore,

$21-13=8$ are boys that prefer chemistry.

If 24 is the sum of the boys that prefer chemistry and biology ⇒

$24-8=16$ are boys that prefer biology.

If we sum $29+16=45$ is the number of students that prefer biology.

If we want to calculate the percentage we need to divide the amount of students that prefer biology by the total of students interviewed and then multiply that number by 100 :

$(\frac{45}{100}).(100)=45$ %

45 % of the students prefer biology.