a. The probability of 2 or more defects if

P(2 or more defects)=P(2 defects)+P(3 defects),

since one item cannot habe both 2 and 3 defects. So,

P(2 or more defects)=f(2)+f(3)=0.4

b.Similarly,

P(1 or more defects)=f(1)+f(2)+f(3)=.11

Therefore, a phone is more likely to have 0 defects.

P(2 or more defects)=P(2 defects)+P(3 defects),

since one item cannot habe both 2 and 3 defects. So,

P(2 or more defects)=f(2)+f(3)=0.4

b.Similarly,

P(1 or more defects)=f(1)+f(2)+f(3)=.11

Therefore, a phone is more likely to have 0 defects.