Answer:
From both approaches P(F or G)=0.667
Step-by-step explanation:
P(F or G)=?
F={9, 10, 11, 12, 13}
G={13,14,15,16}
Finding P(F or G) by counting outcomes in F or G
F or G={9, 10, 11, 12, 13}or {13,14,15,16}
F or G={9, 10, 11, 12,13,14,15,16}
number of outcomes in F or G=n(F or G)=8
S={9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
number of outcomes in S=n(S)=12
P(F or G)=n(F or G)/n(S)
P(F or G)=8/12
P(F or G)=0.667
Finding P(F or G) by addition rule
P(F or G)=P(F)+P(G)-P(F and G)
F={9, 10, 11, 12, 13}
number of outcomes in F=n(F)=5
P(F)=n(F)/n(S)
P(F)=5/12
P(F)=0.417
G={13,14,15,16}
number of outcomes in G=n(G)=4
P(G)=n(G)/n(S)
P(G)=4/12
P(G)=0.333
F and G={9, 10, 11, 12, 13}and {13,14,15,16}
F and G={13}
number of outcomes in F and G=n(F and G)=1
P(F and G)=n(F and G)/n(S)
P(F and G)=1/12
P(F and G)=0.083
P(F or G)=P(F)+P(G)-P(F and G)
P(F or G)=0.417+0.333-0.083
P(F or G)=0.667