Question

there are 20 students in a class. two out of every five of them have a cell phone.
(a) build a diagram that shows, for all students in the class, the number who have a cell phone and the number who dont. make sure to do these steps.

• drag to adjust the number of sections in the diagram below.
• fill in the input box to show how many students are in each section.

number of students in each section:
diagram: total students, with two sections: have a cell phone, do not have a cell phone, with drag handles
(b) using the diagram, find the number of students in the class who have a cell phone.
input box for number of students who have a cell phone

Explanation:

Step1: Find students per section

Total students = 20, split into 5 groups.
$\frac{20}{5} = 4$

Step2: Count phone-owning sections

2 out of 5 sections have phones.
$2 \times 4 = 8$

Step3: Adjust diagram sections

Set 2 sections for "Have a cell phone", 3 sections for "Do not have a cell phone", each section = 4 students.

Answer:

(a) Number of students in each section: $4$
Adjust the diagram to have 2 sections under "Have a cell phone" and 3 sections under "Do not have a cell phone", with each section representing 4 students.
(b) 8 students