Question

I need some help: A survey of 120 persons was conducted at TCC, and it was found that 97 persons carried a cell phone, 12 persons carried a tablet computer, and 9 carried both a cell phone and a tablet. How many people carried a cell phone or a tablet?

Answer 1

100

Explanation:

n(u)=120 total people in survey

n(c)=97 people carrying cell phone

n(t)=12 people carrying tablet

n(c∩t)=9 people carrying both tablet and cell phone

n(c∪t)=? people carrying cell phone or tablet

now,

n(c∪t)= n(c)+n(t) - n(c∩t)

= 97+12-9

=109-9

=100

there fore the number of people carrying cell phone or tablet = 100