What is the probability you pick a student in the school and they prefer to use Tik-Tok OR they are a Junior? (Write as a percent rounded to the nearest hundredth)

Question

Classification	Tik-Tok	Snapchat	Total
Freshman	345	122	467
Sophomore	289	203	492
Junior	178	109	287
Senior	103	189	292
Total	915	623	1538

Answer 1

P(prefer tiktok or a junior) = P(tiktok) + P(junior) - P(tiktok + junior) =

915/1538 + 287/1538 - 178/1538 =

(915 + 287 - 178)/1538 =

1024/1538 = 0.67