Respuesta :
Answer:
a) 36
b) 26
Step-by-step explanation:
Data provided in the question:
Total friends = 8
Number of friends invited to the party = 5
Now,
a) if 2 of the friends are feuding will not attend together
= ( Total choices of selecting 5 friends out of 8 ) - (Choices in which both feuding will attend)
= ⁸C₅ - ⁶C₃
[ here, when both will come we will be left with inviting 3 friends out of 6 as 2 are already fixed. thus ⁶C₃ ]
= [tex]\frac{8!}{5!(8-5)!}-\frac{6!}{3!(6-3)!}[/tex]
= 36
b) if 2 of the friends will only attend together
= Both attend the party + None of them attend the party
= ⁶C₃ + ⁶C₅
= [tex]\frac{6!}{3!(6-3)!}+\frac{6!}{5!(6-5)!}[/tex]
= 26
