Question

how many total have an mp3 player?

Explanation:

Step1: Find the number of people with an MP3 player in each category

People with a cell phone and an MP3 player: \(57\)
People without a cell phone and with an MP3 player: \(13\)

Step2: Calculate the total number of people with an MP3 player

Add the two values: \(57 + 13\)
$$57+13 = 70$$

Answer:

\(70\)