Question

There are 120 students surveyed (30 from each grade). Use the table below to determine what percent chance there is that a student selected at random is in 11th grade or selected Science as their favorite subject? Find P (11th or Science)

Answer 1

Answer: 50 %

Step-by-step explanation:

From the given table the number of 11th students = n(11th)=30

The number of science students n(S)= 6+7+5+7=25

The number of students in 11th and science= n(11th ∩ S)=5

Now, the number of students in 11th grade or selected Science

n(11th ∪ S)=n(11th)+n(S)-n(11th∩S)

⇒n(11th ∪ S)=30+25-5=60

Now, The percent chance there is that a student selected at random is in 11th grade or selected Science as their favorite subject

$=\frac{n(11th\ \cup S )}{120}\times100=\frac{60}{120}\times100=50\%$