Answer:
100
Step-by-step explanation:
n(u)=120 Â total people in survey
n(c)=97 Â Â people carrying cell phone
n(t)=12 Â Â 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
